Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH 4/5] ARM: davinci: enable LEDs default-on trigger in default config
From: David Lechner @ 2016-10-27 15:49 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <669b14c2-7f62-35bc-c8a3-6dde05a99fb1@ti.com>

On 10/27/2016 06:29 AM, Sekhar Nori wrote:
> On Saturday 22 October 2016 12:06 AM, David Lechner wrote:
>> The LEDs default-on trigger is nice to have. For example, it can be used
>> to configure a LED as a power indicator.
>>
>> Signed-off-by: David Lechner <david@lechnology.com>
>> ---
>>  arch/arm/configs/davinci_all_defconfig | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm/configs/davinci_all_defconfig b/arch/arm/configs/davinci_all_defconfig
>> index 9d7f0bc..e380743 100644
>> --- a/arch/arm/configs/davinci_all_defconfig
>> +++ b/arch/arm/configs/davinci_all_defconfig
>> @@ -181,6 +181,7 @@ CONFIG_LEDS_GPIO=m
>>  CONFIG_LEDS_TRIGGERS=y
>>  CONFIG_LEDS_TRIGGER_TIMER=m
>>  CONFIG_LEDS_TRIGGER_HEARTBEAT=m
>> +CONFIG_LEDS_TRIGGER_DEFAULT_ON=y
>
> Can this be module like rest of the triggers? It will come on later, but
> not sure if you care about the difference that much. Having it a module
> will be better for those boards that don't need it.
>
> Thanks,
> Sekhar
>

Yes, module is OK here.

^ permalink raw reply

* [PATCH v3 2/3] drm: zte: add initial vou drm driver
From: Shawn Guo @ 2016-10-27 15:32 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20161020122958.GC10198@joana>

Hi Gustavo,

Thanks for looking at the patch.

> 2016-10-20 Shawn Guo <shawn.guo@linaro.org>:
> 
> > It adds the initial ZTE VOU display controller DRM driver.  There are
> > still some features to be added, like overlay plane, scaling, and more
> > output devices support.  But it's already useful with dual CRTCs and
> > HDMI monitor working.
> >
> > Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

<snip>

> > +static void zx_hdmi_connector_destroy(struct drm_connector *connector)
> > +{
> > +     drm_connector_unregister(connector);
> 
> drm_connector_unregister() is not needed anymore. DRM core will call it
> for you.
> 
> > +     drm_connector_cleanup(connector);
> > +}
> > +
> > +static const struct drm_connector_funcs zx_hdmi_connector_funcs = {
> > +     .dpms = drm_atomic_helper_connector_dpms,
> > +     .fill_modes = drm_helper_probe_single_connector_modes,
> > +     .detect = zx_hdmi_connector_detect,
> > +     .destroy = zx_hdmi_connector_destroy,
> 
> Then here you can use drm_connector_cleanup() directly.

Okay, will do.

> > +     .reset = drm_atomic_helper_connector_reset,
> > +     .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> > +     .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> > +};

<snip>

> > +static void zx_crtc_atomic_begin(struct drm_crtc *crtc,
> > +                              struct drm_crtc_state *state)
> > +{
> > +     struct drm_pending_vblank_event *event = crtc->state->event;
> > +
> > +     if (!event)
> > +             return;
> > +
> > +     crtc->state->event = NULL;
> > +
> > +     spin_lock_irq(&crtc->dev->event_lock);
> > +     if (drm_crtc_vblank_get(crtc) == 0)
> > +             drm_crtc_arm_vblank_event(crtc, event);
> > +     else
> > +             drm_crtc_send_vblank_event(crtc, event);
> > +     spin_unlock_irq(&crtc->dev->event_lock);
> 
> I think you may want to send the vblank event to userspace after you
> commit your planes, and not before.

I guess you are suggesting that the code should be implemented in
.atomic_flush hook instead, right?

> > +}
> > +
> > +static const struct drm_crtc_helper_funcs zx_crtc_helper_funcs = {
> > +     .enable = zx_crtc_enable,
> > +     .disable = zx_crtc_disable,
> > +     .atomic_begin = zx_crtc_atomic_begin,
> > +};
> > +
> > +static const struct drm_crtc_funcs zx_crtc_funcs = {
> > +     .destroy = drm_crtc_cleanup,
> > +     .set_config = drm_atomic_helper_set_config,
> > +     .page_flip = drm_atomic_helper_page_flip,
> > +     .reset = drm_atomic_helper_crtc_reset,
> > +     .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
> > +     .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
> > +};
> > +
> > +static int zx_crtc_init(struct drm_device *drm, struct zx_vou_hw *vou,
> > +                     enum vou_chn_type chn_type)
> > +{
> > +     struct device *dev = vou->dev;
> > +     struct zx_layer_data data;
> > +     struct zx_crtc *zcrtc;
> > +     int ret;
> > +
> > +     zcrtc = devm_kzalloc(dev, sizeof(*zcrtc), GFP_KERNEL);
> > +     if (!zcrtc)
> > +             return -ENOMEM;
> > +
> > +     zcrtc->vou = vou;
> > +     zcrtc->chn_type = chn_type;
> > +
> > +     if (chn_type == VOU_CHN_MAIN) {
> > +             data.layer = vou->osd + MAIN_GL_OFFSET;
> > +             data.csc = vou->osd + MAIN_CSC_OFFSET;
> > +             data.hbsc = vou->osd + MAIN_HBSC_OFFSET;
> > +             data.rsz = vou->otfppu + MAIN_RSZ_OFFSET;
> > +             zcrtc->chnreg = vou->osd + OSD_MAIN_CHN;
> > +             zcrtc->regs = &main_crtc_regs;
> > +             zcrtc->bits = &main_crtc_bits;
> > +     } else {
> > +             data.layer = vou->osd + AUX_GL_OFFSET;
> > +             data.csc = vou->osd + AUX_CSC_OFFSET;
> > +             data.hbsc = vou->osd + AUX_HBSC_OFFSET;
> > +             data.rsz = vou->otfppu + AUX_RSZ_OFFSET;
> > +             zcrtc->chnreg = vou->osd + OSD_AUX_CHN;
> > +             zcrtc->regs = &aux_crtc_regs;
> > +             zcrtc->bits = &aux_crtc_bits;
> > +     }
> > +
> > +     zcrtc->pixclk = devm_clk_get(dev, (chn_type == VOU_CHN_MAIN) ?
> > +                                       "main_wclk" : "aux_wclk");
> > +     if (IS_ERR(zcrtc->pixclk)) {
> > +             ret = PTR_ERR(zcrtc->pixclk);
> > +             dev_err(dev, "failed to get pix clk: %d\n", ret);
> 
> DRM_ERROR() - here and in other places in your patch

I will follow Sean's suggestion to use DRM_DEV_* for these messages.

Shawn

^ permalink raw reply

* [PATCH v4] ARM: davinci: da8xx: Remove duplicated defines
From: Alexandre Bailon @ 2016-10-27 15:32 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1477582356-28156-1-git-send-email-abailon@baylibre.com>

Some macro for DA8xx CFGCHIP are defined in usb-davinci.h,
but da8xx-cfgchip.h intend to replace them.
Remove duplicated defines between da8xx-cfgchip.h and usb-davinci.h

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
---
 arch/arm/mach-davinci/board-da830-evm.c     |  5 +++--
 arch/arm/mach-davinci/board-omapl138-hawk.c |  3 ++-
 include/linux/platform_data/usb-davinci.h   | 23 -----------------------
 3 files changed, 5 insertions(+), 26 deletions(-)

diff --git a/arch/arm/mach-davinci/board-da830-evm.c b/arch/arm/mach-davinci/board-da830-evm.c
index 3d8cf8c..df1f409 100644
--- a/arch/arm/mach-davinci/board-da830-evm.c
+++ b/arch/arm/mach-davinci/board-da830-evm.c
@@ -18,6 +18,7 @@
 #include <linux/i2c.h>
 #include <linux/i2c/pcf857x.h>
 #include <linux/platform_data/at24.h>
+#include <linux/mfd/da8xx-cfgchip.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
 #include <linux/spi/spi.h>
@@ -116,7 +117,7 @@ static __init void da830_evm_usb_init(void)
 	cfgchip2 = __raw_readl(DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP2_REG));
 
 	/* USB2.0 PHY reference clock is 24 MHz */
-	cfgchip2 &= ~CFGCHIP2_REFFREQ;
+	cfgchip2 &= ~CFGCHIP2_REFFREQ_MASK;
 	cfgchip2 |=  CFGCHIP2_REFFREQ_24MHZ;
 
 	/*
@@ -133,7 +134,7 @@ static __init void da830_evm_usb_init(void)
 	 * controller won't be able to drive VBUS thinking that it's a B-device.
 	 * Otherwise, we want to use the OTG mode and enable VBUS comparators.
 	 */
-	cfgchip2 &= ~CFGCHIP2_OTGMODE;
+	cfgchip2 &= ~CFGCHIP2_OTGMODE_MASK;
 #ifdef	CONFIG_USB_MUSB_HOST
 	cfgchip2 |=  CFGCHIP2_FORCE_HOST;
 #else
diff --git a/arch/arm/mach-davinci/board-omapl138-hawk.c b/arch/arm/mach-davinci/board-omapl138-hawk.c
index ee62486..e1efa10 100644
--- a/arch/arm/mach-davinci/board-omapl138-hawk.c
+++ b/arch/arm/mach-davinci/board-omapl138-hawk.c
@@ -13,6 +13,7 @@
 #include <linux/init.h>
 #include <linux/console.h>
 #include <linux/gpio.h>
+#include <linux/mfd/da8xx-cfgchip.h>
 #include <linux/platform_data/gpio-davinci.h>
 
 #include <asm/mach-types.h>
@@ -254,7 +255,7 @@ static __init void omapl138_hawk_usb_init(void)
 	/* Setup the Ref. clock frequency for the HAWK at 24 MHz. */
 
 	cfgchip2 = __raw_readl(DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP2_REG));
-	cfgchip2 &= ~CFGCHIP2_REFFREQ;
+	cfgchip2 &= ~CFGCHIP2_REFFREQ_MASK;
 	cfgchip2 |=  CFGCHIP2_REFFREQ_24MHZ;
 	__raw_writel(cfgchip2, DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP2_REG));
 
diff --git a/include/linux/platform_data/usb-davinci.h b/include/linux/platform_data/usb-davinci.h
index e0bc4ab..0926e99 100644
--- a/include/linux/platform_data/usb-davinci.h
+++ b/include/linux/platform_data/usb-davinci.h
@@ -11,29 +11,6 @@
 #ifndef __ASM_ARCH_USB_H
 #define __ASM_ARCH_USB_H
 
-/* DA8xx CFGCHIP2 (USB 2.0 PHY Control) register bits */
-#define CFGCHIP2_PHYCLKGD	(1 << 17)
-#define CFGCHIP2_VBUSSENSE	(1 << 16)
-#define CFGCHIP2_RESET		(1 << 15)
-#define CFGCHIP2_OTGMODE	(3 << 13)
-#define CFGCHIP2_NO_OVERRIDE	(0 << 13)
-#define CFGCHIP2_FORCE_HOST	(1 << 13)
-#define CFGCHIP2_FORCE_DEVICE 	(2 << 13)
-#define CFGCHIP2_FORCE_HOST_VBUS_LOW (3 << 13)
-#define CFGCHIP2_USB1PHYCLKMUX	(1 << 12)
-#define CFGCHIP2_USB2PHYCLKMUX	(1 << 11)
-#define CFGCHIP2_PHYPWRDN	(1 << 10)
-#define CFGCHIP2_OTGPWRDN	(1 << 9)
-#define CFGCHIP2_DATPOL 	(1 << 8)
-#define CFGCHIP2_USB1SUSPENDM	(1 << 7)
-#define CFGCHIP2_PHY_PLLON	(1 << 6)	/* override PLL suspend */
-#define CFGCHIP2_SESENDEN	(1 << 5)	/* Vsess_end comparator */
-#define CFGCHIP2_VBDTCTEN	(1 << 4)	/* Vbus comparator */
-#define CFGCHIP2_REFFREQ	(0xf << 0)
-#define CFGCHIP2_REFFREQ_12MHZ	(1 << 0)
-#define CFGCHIP2_REFFREQ_24MHZ	(2 << 0)
-#define CFGCHIP2_REFFREQ_48MHZ	(3 << 0)
-
 struct	da8xx_ohci_root_hub;
 
 typedef void (*da8xx_ocic_handler_t)(struct da8xx_ohci_root_hub *hub,
-- 
2.7.3

^ permalink raw reply related

* [PATCH v4] Remove duplicated defines (was [PATCH v3] Fix some potential warnings)
From: Alexandre Bailon @ 2016-10-27 15:32 UTC (permalink / raw)
  To: linux-arm-kernel

Remove duplicated defines before they cause warning.

Change in V2:
Update the d830 evm board file to use the da8xx-cfgchip.h
These changes are required as I'm sending this patch apart from
the series "[PATCH/RFT v2 00/17] Add DT support for ohci-da8xx"

Changes in v3:
* Change the patch description to better respect what the patch fix.
* Sorted new header sorted in alphabetical order.

Alexandre Bailon (1):
  ARM: davinci: da8xx: Remove duplicated defines

 arch/arm/mach-davinci/board-da830-evm.c     |  5 +++--
 arch/arm/mach-davinci/board-omapl138-hawk.c |  3 ++-
 include/linux/platform_data/usb-davinci.h   | 23 -----------------------
 3 files changed, 5 insertions(+), 26 deletions(-)

-- 
2.7.3

^ permalink raw reply

* [RFC PATCH 0/8] arm64: Add a compat vDSO
From: Dmitry Safonov @ 2016-10-27 15:23 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20160908140103.7468-1-kevin.brodsky@arm.com>

2016-09-08 17:00 GMT+03:00 Kevin Brodsky <kevin.brodsky@arm.com>:
> Hi,
>
> This series adds support for a compat (AArch32) vDSO, providing two
> userspace functionalities to compat processes:
>
> * "Virtual" time syscalls (gettimeofday and clock_gettime). The
>   implementation is an adaptation of the arm vDSO (vgettimeofday.c),
>   sharing the data page with the 64-bit vDSO.
>
> * sigreturn trampolines, following the example of the 64-bit vDSO
>   (sigreturn.S), but slightly more complicated because we provide A32
>   and T32 variants for both sigreturn and rt_sigreturn.
>
> The first point brings the performance improvement expected of a vDSO,
> by implementing time syscalls directly in userspace. The second point
> allows us to get rid of the compat vector page, at the expense of the
> kuser helpers (this is one reason for not enabling the compat vDSO by
> default).
>
> Unfortunately, this time we cannot escape using a 32-bit toolchain. To
> build the compat VDSO, CONFIG_COMPAT_VDSO must be set *and*
> CROSS_COMPILE_ARM32 must be defined to the prefix of a 32-bit compiler.
> Failure to do so will not prevent building the kernel, but a warning
> will be printed and the compat vDSO will not be built.
>
> I have only tested the series with a 64-bit userspace (+ 32-bit glibc).
> Testing it with a 32-bit userspace would be very welcome.

Hi, what's up with these patches, are you gonna resend them or prepare
a new version?

> Thanks,
> Kevin
>
> Kevin Brodsky (8):
>   arm64: Refactor vDSO setup
>   arm64: compat: Add time-related syscall numbers
>   arm64: compat: Expose offset to registers in sigframes
>   arm64: compat: Add a 32-bit vDSO
>   arm64: compat: 32-bit vDSO setup
>   arm64: elf: Set AT_SYSINFO_EHDR in compat processes
>   arm64: compat: Use vDSO sigreturn trampolines if available
>   arm64: Wire up and expose the new compat vDSO
>
>  arch/arm64/Kconfig                       |  20 +++
>  arch/arm64/Makefile                      |  20 ++-
>  arch/arm64/include/asm/elf.h             |  15 +-
>  arch/arm64/include/asm/signal32.h        |  46 +++++
>  arch/arm64/include/asm/unistd.h          |   2 +
>  arch/arm64/include/asm/vdso.h            |   3 +
>  arch/arm64/kernel/Makefile               |   8 +-
>  arch/arm64/kernel/asm-offsets.c          |  13 ++
>  arch/arm64/kernel/signal32.c             |  61 ++-----
>  arch/arm64/kernel/vdso.c                 | 198 ++++++++++++---------
>  arch/arm64/kernel/vdso32/Makefile        | 121 +++++++++++++
>  arch/arm64/kernel/vdso32/sigreturn.S     |  86 +++++++++
>  arch/arm64/kernel/vdso32/vdso.S          |  32 ++++
>  arch/arm64/kernel/vdso32/vdso.lds.S      |  98 +++++++++++
>  arch/arm64/kernel/vdso32/vgettimeofday.c | 294 +++++++++++++++++++++++++++++++
>  15 files changed, 883 insertions(+), 134 deletions(-)
>  create mode 100644 arch/arm64/kernel/vdso32/Makefile
>  create mode 100644 arch/arm64/kernel/vdso32/sigreturn.S
>  create mode 100644 arch/arm64/kernel/vdso32/vdso.S
>  create mode 100644 arch/arm64/kernel/vdso32/vdso.lds.S
>  create mode 100644 arch/arm64/kernel/vdso32/vgettimeofday.c

-- 
             Dmitry

^ permalink raw reply

* [PATCH 5/5] tty: amba-pl011: Add earlycon support for SBSA UART
From: Greg Kroah-Hartman @ 2016-10-27 15:18 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <7edb183d-2376-0f09-a3ea-3bf78971609d@huawei.com>

On Mon, Oct 24, 2016 at 11:59:20AM +0800, Kefeng Wang wrote:
> Hi Greg, any more comments, thanks.

Never wait, just resend if you have comments and you know you have to
fix them up...

^ permalink raw reply

* [RFC PATCH 0/5] Add an overlay manager to handle board capes
From: Hans de Goede @ 2016-10-27 15:13 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <CAL_JsqL9yWBj0yYE54XGi87YPGugGAACzr=CuW6dk5kk3EuyCA@mail.gmail.com>

Hi,

On 27-10-16 15:41, Rob Herring wrote:
> Please Cc the maintainers of drivers/of/.
>
> + Frank R, Hans, Dmitry S
>
> On Wed, Oct 26, 2016 at 9:57 AM, Antoine Tenart
> <antoine.tenart@free-electrons.com> wrote:
>> Hi all,
>>
>> Many boards now come with dips and compatible capes; among others the
>> C.H.I.P, or Beaglebones. All these boards have a kernel implementing an
>> out-of-tree "cape manager" which is used to detected capes, retrieve
>> their description and apply a corresponding overlay. This series is an
>> attempt to start a discussion, with an implementation of such a manager
>> which is somehow generic (i.e. formats or cape detectors can be added).
>> Other use cases could make use of this manager to dynamically load dt
>> overlays based on some input / hw presence.
>
> I'd like to see an input source be the kernel command line and/or a DT
> chosen property. Another overlay manager was proposed not to long
> ago[1] as well. There's also the Allwinner tablet use case from Hans
> where i2c devices are probed and detected. That's not using overlays
> currently, but maybe could.

Actually I'm currently thinking in a different direction, which I
think will be good for the boards where some ICs are frequently
replaced by 2nd (and 3th and 4th) sources, rather then that we're
dealing with an extension connector with capes / daughter boards.

Although there is some overlap I'm starting to think that we need to
treat these 2 cases differently. Let me quickly copy and paste
the basic idea I've for the 2nd source touchscreen / accelerometer
chip case:

"""
The kernel actually already has a detect() method in struct i2c_driver,
we could use that (we would need to implement it in drivers which do not
have it yet). Note on second thought it seems it may be better to use
probe() for this, see below.

Then we could have something like this in dt:

&i2c0 {
     touchscreen1: gsl1680 at 40 {
         reg = <0x40>;
         compatible = "silead,gsl1680";
         enable-gpios = <&pio 7 1 GPIO_ACTIVE_HIGH>; /* PH1 */
         status = "disabled";
     };

     touchscreen2: ektf2127 at 15 {
         reg = <0x15>;
         compatible = "elan,ektf2127";
         enable-gpios = <&pio 7 1 GPIO_ACTIVE_HIGH>; /* PH1 */
         status = "disabled";
     };

     i2c-probe-stop-at-first-match-0 = <&touchscreen1>, <&touchscreen2>;
     i2c-probe-stop-at-first-match-1 = <&accelerometer1>, <&accelerometer2>;
}

Which would make the i2c subsys call detect (*) on each device, until
a device is found. Likewise we could have a "i2c-probe-all" property
which also walks a list of phandles but does not stop on the first
match.

...

*) Yes this sounds Linux specific, but it really is just "execute to-be-probed
device compatible specific detection method"
"""

This does not 100% solve all q8 issues (see the "Add Allwinner Q8 tablets
hardware manager" thread), but does solve quite a bit of the use-case
and this matches what many vendor os-images (typically android) are
actually doing for these kind of boards.

As for the bits this does not solve, those are mostly board specific details
which cannot be probed at all, and on x86 are typically solved in the device
driver by doing a dmi check to identify the board and then apply a board
specific workaround in the driver.

I've come to believe that we should similarly delegate dealing this to device
drivers in the devicetree case. Note that dt should still of course fully
describe the hardware for normal hardware, the driver would just need to care
about weird board quirks in certain exceptions.

A more interesting problem here is that dt does not have something like
DMI, there is the machine compatible, but that typically does not contain
board revision info (where as DMI often does). I believe that this is
actually something which should be fixed at the bootloader level
have it prepend a new machine compatible which contains revision info.

Hmm, if we make the bootloader prepend a new machine compatible which contains
revision info, we could then trigger quirks on this and in some cases avoid
the need for dealing with board quirks in the driver ...

Note this is all very specific to dealing with board (revision) variants,
for add-ons having the bootloader add info to the machine compatible does
not seem the right solution.

Regards,

Hans




>
> Another thing to consider is different sources of overlays. Besides in
> the filesystem, overlays could be built into the kernel (already
> supported), embedded in the dtb (as the other overlay mgr did) or we
> could extend FDT format to append them.
>
>> The proposed design is a library which can be used by detector drivers
>> to parse headers and load the corresponding overlay. Helpers are
>> provided for this purpose. The whole thing is divided into 3 entities:
>>
>> - The parser which is project-specific (to allow supporting headers
>>   already into the wild). It registers a function parsing an header's
>>   data and filling one or more strings which will be used to find
>>   matching dtbo on the fs.
>>
>> - The overlay manager helpers allowing to parse a header to retrieve
>>   the previously mentioned strings and to load a compatible overlay.
>>
>> - The detectors which are used to detect capes and get their description
>>   (to be parsed).
>
> What about things like power has to be turned on first to detect
> boards and read their ID? I think this needs to be tied into the
> driver model. Though, don't go sticking cape mgr nodes into DT. Maybe
> a driver gets bound to a connector node, but we've got to sort out
> connector bindings first.
>
>> An example of parser and detector is given, compatible with what's done
>> for the C.H.I.P. As the w1 framework is really bad (and we should
>> probably do something about that) the detector code is far from being
>> perfect; but that's not related to what we try to achieve here.
>>
>> The actual implementation has a limitation: the detectors cannot be
>> built-in the kernel image as they would likely detect capes at boot time
>> but will fail to get their corresponding dt overlays as the fs isn't
>> mounted yet. The only case this can work is when dt overlays are
>> built-in firmwares. This isn't an issue for the C.H.I.P. use case right
>> now. There was a discussion about making an helper to wait for the
>> rootfs to be mount but the answer was "this is the driver's problem".
>
> I thought there are firmware loading calls that will wait. I think
> this all needs to work asynchronously both for firmware loading and
> because w1 is really slow.
>
>> I'd like to get comments, specifically from people using custom cape
>> managers, to see if this could fill their needs (with I guess some
>> modifications).
>
> Having 2 would certainly give a better sense this is generic.
>
> Rob
>
> [1] https://patchwork.ozlabs.org/patch/667805/
>

^ permalink raw reply

* [alsa-devel] [linux-sunxi] [PATCH v5 4/7] ASoC: sunxi: Add sun8i I2S driver
From: Jean-Francois Moine @ 2016-10-27 15:13 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20161024123449.npo4grdlbrj4tcsj@lukather>

On Mon, 24 Oct 2016 14:34:49 +0200
Maxime Ripard <maxime.ripard@free-electrons.com> wrote:

> Hi,
> 
> On Sun, Oct 23, 2016 at 09:45:03AM +0200, Jean-Francois Moine wrote:
> > On Sun, 23 Oct 2016 09:33:16 +0800
> > Chen-Yu Tsai <wens@csie.org> wrote:
> > 
> > > > Note: This driver is closed to the sun4i-i2s except that:
> > > > - it handles the H3
> > > 
> > > If it's close to sun4i-i2s, you should probably rework that one to support
> > > the newer SoCs.
> > > 
> > > > - it creates the sound card (with sun4i-i2s, the sound card is created
> > > >   by the CODECs)
> > > 
> > > I think this is wrong. I2S is only the DAI. You typically have a separate
> > > platform driver for the whole card, or just use simple-card.
> > 
> > An other device is not needed. The layout is simple:
> > 	I2S_controller (CPU DAI) <-> HDMI_CODEC (CODEC DAI)
> > The HDMI CODEC is supported by the HDMI video driver (only one device),
> > so, it cannot be the card device.
> > ASoC does not use the CPU DAI device (I2S_controller), so, it is
> > natural to use it to handle the card.
> 
> Still, duplicating the driver is not the solution. I agree with
> Chen-Yu that we want to leverage the driver that is already there.

Hi Maxime and Chen-Yu,

After looking at the sun4i-i2s, I found 2 solutions for re-using its
code in the DE2 HDMI context:

1) either to split the sun4i-i2s driver into common I/O functions and
   slave CPU DAI,

2) or to move the sun4i-i2s into a master CPU DAI.

(
 some explanation about 'master' and 'slave': the master is the
 component the device of which is also the sound card.
 As the sound card uses the 'drvdata' of the device, this drvdata pointer
 cannot be used by the master.
 In the actual implementations:
  - sun4i-i2s
	master:	card dev = codec dev, drvdata -> card
	slave:	i2s dev (CPU DAI), drvdata -> i2s data
  - sun8i-i2s
	master:	card dev = i2s dev (CPU DAI), drvdata -> card
	slave:	codec dev (hdmi), drvdata -> codec data (audio/video)
)

In the case 1, there is no functional change, just a source split.
The sun8i-i2s will then use the common I/O functions.

In the case 2, the CODECs using the sun4i-i2s would have to move to
slave CODEC DAI, i.e. the card is created by the sun4i-i2s code.
In the 4.9, there is only one codec (sun4i-codec), so, the change
is just to move the card creation and the use of drvdata in both
codes.

In either cases, I could not check if this changes raise some
regression on the sun4i SoCs side. Then, I'd be glad to know:
- which solution suits you?
- are you ready to do and test the needed changes at the sun4i side?

-- 
Ken ar c'henta?	|	      ** Breizh ha Linux atav! **
Jef		|		http://moinejf.free.fr/

^ permalink raw reply

* [PATCH] KVM: arm/arm64: Kick VCPUs when queueing already pending IRQs
From: Shih-Wei Li @ 2016-10-27 15:08 UTC (permalink / raw)
  To: linux-arm-kernel

In cases like IPI, we could be queueing an interrupt for a VCPU
that is already running and is not about to exit, because the
VCPU has entered the VM with the interrupt pending and would
not trap on EOI'ing that interrupt. This could result to delays
in interrupt deliveries or even loss of interrupts.
To guarantee prompt interrupt injection, here we have to try to
kick the VCPU.

Signed-off-by: Shih-Wei Li <shihwei@cs.columbia.edu>
---

I've tested the code with an IPI test built on kvm-unit-test, which
measures the cycles spent between one VCPU sending IPI to a target
VCPU that busy loops in the VM, until the target VCPU ACKs and EOIs
the IPI. The patch here can improve the performance in such case by
more than 5000 cycles.

 virt/kvm/arm/vgic/vgic.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index b419a11..07cf239 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -273,6 +273,17 @@ retry:
 		 * no more work for us to do.
 		 */
 		spin_unlock(&irq->irq_lock);
+
+		/*
+		 * If the VCPU is not NULL, we could be queueing an
+		 * edge-triggered interrupt for a VCPU which is already
+		 * running and is not about to exit, because the VCPU has
+		 * entered the VM with the interrupt pending and it wouldn't
+		 * trap on EOI. To ensure prompt delivery of that interrupt,
+		 * we have to try to kick the VCPU.
+		 */
+		if (vcpu)
+			kvm_vcpu_kick(vcpu);
 		return false;
 	}
 
-- 
1.9.1

^ permalink raw reply related

* [RFC PATCH 1/5] of: introduce the overlay manager
From: Pantelis Antoniou @ 2016-10-27 15:07 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20161026145756.21689-2-antoine.tenart@free-electrons.com>

Hi Antoine,

> On Oct 26, 2016, at 17:57 , Antoine Tenart <antoine.tenart@free-electrons.com> wrote:
> 
> The overlay manager is an in-kernel library helping to handle dt overlay
> loading when using capes.
> 

Code related comments

> Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
> ---
> drivers/of/Kconfig                           |   2 +
> drivers/of/Makefile                          |   1 +
> drivers/of/overlay-manager/Kconfig           |   6 +
> drivers/of/overlay-manager/Makefile          |   1 +
> drivers/of/overlay-manager/overlay-manager.c | 199 +++++++++++++++++++++++++++
> include/linux/overlay-manager.h              |  38 +++++
> 6 files changed, 247 insertions(+)
> create mode 100644 drivers/of/overlay-manager/Kconfig
> create mode 100644 drivers/of/overlay-manager/Makefile
> create mode 100644 drivers/of/overlay-manager/overlay-manager.c
> create mode 100644 include/linux/overlay-manager.h
> 
> diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
> index bc07ad30c9bf..e57aeaf0bf4f 100644
> --- a/drivers/of/Kconfig
> +++ b/drivers/of/Kconfig
> @@ -116,4 +116,6 @@ config OF_OVERLAY
> config OF_NUMA
> 	bool
> 
> +source "drivers/of/overlay-manager/Kconfig"
> +
> endif # OF
> diff --git a/drivers/of/Makefile b/drivers/of/Makefile
> index d7efd9d458aa..d738fd41271f 100644
> --- a/drivers/of/Makefile
> +++ b/drivers/of/Makefile
> @@ -16,3 +16,4 @@ obj-$(CONFIG_OF_OVERLAY) += overlay.o
> obj-$(CONFIG_OF_NUMA) += of_numa.o
> 
> obj-$(CONFIG_OF_UNITTEST) += unittest-data/
> +obj-y += overlay-manager/
> diff --git a/drivers/of/overlay-manager/Kconfig b/drivers/of/overlay-manager/Kconfig
> new file mode 100644
> index 000000000000..eeb76054dcb8
> --- /dev/null
> +++ b/drivers/of/overlay-manager/Kconfig
> @@ -0,0 +1,6 @@
> +config OF_OVERLAY_MGR
> +	bool "Device Tree Overlay Manager"
> +	depends on OF_OVERLAY
> +	help
> +	  Enable the overlay manager to handle automatic overlay loading when
> +	  devices are detected.
> diff --git a/drivers/of/overlay-manager/Makefile b/drivers/of/overlay-manager/Makefile
> new file mode 100644
> index 000000000000..86d2b53950e7
> --- /dev/null
> +++ b/drivers/of/overlay-manager/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_OF_OVERLAY_MGR)			+= overlay-manager.o
> diff --git a/drivers/of/overlay-manager/overlay-manager.c b/drivers/of/overlay-manager/overlay-manager.c
> new file mode 100644
> index 000000000000..a725d7e24d38
> --- /dev/null
> +++ b/drivers/of/overlay-manager/overlay-manager.c
> @@ -0,0 +1,199 @@
> +/*
> + * Copyright (C) 2016 - Antoine Tenart <antoine.tenart@free-electrons.com>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/firmware.h>
> +#include <linux/list.h>
> +#include <linux/of.h>
> +#include <linux/of_fdt.h>
> +#include <linux/overlay-manager.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +
> +struct overlay_mgr_overlay {
> +	struct list_head list;
> +	char *name;
> +};
> +
> +LIST_HEAD(overlay_mgr_overlays);
> +LIST_HEAD(overlay_mgr_formats);
> +DEFINE_SPINLOCK(overlay_mgr_lock);
> +DEFINE_SPINLOCK(overlay_mgr_format_lock);
> +

Is there a reason for using spinlocks here? OF uses a mutex for
locking since we don?t expect OF manipulation occurring in a
non schedulable context.

> +/*
> + * overlay_mgr_register_format()
> + *
> + * Adds a new format candidate to the list of supported formats. The registered
> + * formats are used to parse the headers stored on the dips.
> + */
> +int overlay_mgr_register_format(struct overlay_mgr_format *candidate)
> +{
> +	struct overlay_mgr_format *format;
> +	int err = 0;
> +
> +	spin_lock(&overlay_mgr_format_lock);
> +
> +	/* Check if the format is already registered */
> +	list_for_each_entry(format, &overlay_mgr_formats, list) {
> +		if (!strcpy(format->name, candidate->name)) {
> +			err = -EEXIST;
> +			goto err;
> +		}
> +	}
> +
> +	list_add_tail(&candidate->list, &overlay_mgr_formats);
> +
> +err:
> +	spin_unlock(&overlay_mgr_format_lock);
> +	return err;
> +}
> +EXPORT_SYMBOL_GPL(overlay_mgr_register_format);
> +
> +/*
> + * overlay_mgr_parse()
> + *
> + * Parse raw data with registered format parsers. Fills the candidate string if
> + * one parser understood the raw data format.
> + */
> +int overlay_mgr_parse(struct device *dev, void *data, char ***candidates,
> +		      unsigned *n)
> +{

The two argument format is not very readable. Perhaps use a structure instead?

> +	struct list_head *pos, *tmp;
> +	struct overlay_mgr_format *format;
> +
> +	list_for_each_safe(pos, tmp, &overlay_mgr_formats) {
> +		format = list_entry(pos, struct overlay_mgr_format, list);
> +
> +		format->parse(dev, data, candidates, n);
> +		if (n > 0)
> +			return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(overlay_mgr_parse);
> +
> +static int overlay_mgr_check_overlay(struct device_node *node)
> +{
> +	struct property *p;
> +	const char *str = NULL;
> +
> +	p = of_find_property(node, "compatible", NULL);
> +	if (!p)
> +		return -EINVAL;
> +
> +	do {
> +		str = of_prop_next_string(p, str);
> +		if (of_machine_is_compatible(str))
> +			return 0;

I think this is very similar to the way of_match_node works.
Find a way to use that instead?

> +	} while (str);
> +
> +	return -EINVAL;
> +}
> +
> +/*
> + * _overlay_mgr_insert()
> + *
> + * Try to request and apply an overlay given a candidate name.
> + */
> +static int _overlay_mgr_apply(struct device *dev, char *candidate)
> +{
> +	struct overlay_mgr_overlay *overlay;
> +	struct device_node *node;
> +	const struct firmware *firmware;
> +	char *firmware_name;
> +	int err = 0;
> +
> +	spin_lock(&overlay_mgr_lock);
> +
> +	list_for_each_entry(overlay, &overlay_mgr_overlays, list) {
> +		if (!strcmp(overlay->name, candidate)) {
> +			dev_err(dev, "overlay already loaded\n");
> +			err = -EEXIST;
> +			goto err_lock;
> +		}
> +	}
> +
> +	overlay = devm_kzalloc(dev, sizeof(*overlay), GFP_KERNEL);
> +	if (!overlay) {
> +		err = -ENOMEM;
> +		goto err_lock;
> +	}
> +

spinlock and possibly sleeping?

> +	overlay->name = candidate;
> +
> +	firmware_name = kasprintf(GFP_KERNEL, "overlay-%s.dtbo", candidate);
> +	if (!firmware_name) {
> +		err = -ENOMEM;
> +		goto err_free;
> +	}
> +
> +	dev_info(dev, "requesting firmware '%s'\n", firmware_name);
> +
> +	err = request_firmware_direct(&firmware, firmware_name, dev);
> +	if (err) {
> +		dev_info(dev, "failed to request firmware '%s'\n",
> +			 firmware_name);
> +		goto err_free;
> +	}
> +

Same here.

> +	of_fdt_unflatten_tree((unsigned long *)firmware->data, NULL, &node);
> +	if (!node) {
> +		dev_err(dev, "failed to unflatted tree\n");
> +		err = -EINVAL;
> +		goto err_fw;
> +	}
> +
> +	of_node_set_flag(node, OF_DETACHED);
> +
> +	err = of_resolve_phandles(node);
> +	if (err) {
> +		dev_err(dev, "failed to resolve phandles: %d\n", err);
> +		goto err_fw;
> +	}
> +
> +	err = overlay_mgr_check_overlay(node);
> +	if (err) {
> +		dev_err(dev, "overlay checks failed: %d\n", err);
> +		goto err_fw;
> +	}
> +
> +	err = of_overlay_create(node);
> +	if (err < 0) {
> +		dev_err(dev, "failed to create overlay: %d\n", err);
> +		goto err_fw;
> +	}
> +
> +	list_add_tail(&overlay->list, &overlay_mgr_overlays);
> +
> +	dev_info(dev, "loaded firmware '%s'\n", firmware_name);
> +
> +	spin_unlock(&overlay_mgr_lock);
> +	return 0;
> +
> +err_fw:
> +	release_firmware(firmware);
> +err_free:
> +	devm_kfree(dev, overlay);
> +err_lock:
> +	spin_unlock(&overlay_mgr_lock);
> +	return err;
> +}
> +
> +int overlay_mgr_apply(struct device *dev, char **candidates, unsigned n)
> +{
> +	int i, ret;
> +
> +	for (i=0; i < n; i++) {
> +		ret = _overlay_mgr_apply(dev, candidates[i]);
> +		if (!ret)
> +			return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(overlay_mgr_apply);
> diff --git a/include/linux/overlay-manager.h b/include/linux/overlay-manager.h
> new file mode 100644
> index 000000000000..8adcc4f5ddf6
> --- /dev/null
> +++ b/include/linux/overlay-manager.h
> @@ -0,0 +1,38 @@
> +/*
> + * Copyright (C) 2016 - Antoine Tenart <antoine.tenart@free-electrons.com>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#ifndef __OVERLAY_MGR_H__
> +#define __OVERLAY_MGR_H__
> +
> +#include <linux/device.h>
> +#include <linux/list.h>
> +#include <linux/sizes.h>
> +
> +#define OVERLAY_MGR_DIP_MAX_SZ		SZ_128
> +
> +struct overlay_mgr_format {
> +	struct list_head list;
> +	char *name;
> +	int (*parse)(struct device *dev, void *data, char ***candidates,
> +		     unsigned *n);
> +};
> +
> +int overlay_mgr_register_format(struct overlay_mgr_format *candidate);
> +int overlay_mgr_parse(struct device *dev, void *data, char ***candidates,
> +		      unsigned *n);
> +int overlay_mgr_apply(struct device *dev, char **candidates, unsigned n);
> +
> +#define dip_convert(field)                                      \
> +        (                                                       \
> +                (sizeof(field) == 1) ? field :                  \
> +                (sizeof(field) == 2) ? be16_to_cpu(field) :     \
> +                (sizeof(field) == 4) ? be32_to_cpu(field) :     \
> +                -1                                              \
> +        )
> +
> +#endif /* __OVERLAY_MGR_H__ */
> -- 
> 2.10.1
> 

^ permalink raw reply

* [PATCH v2] ARM: dts: imx53-qsb: Fix regulator constraints
From: Fabio Estevam @ 2016-10-27 15:06 UTC (permalink / raw)
  To: linux-arm-kernel

Since commit fa93fd4ecc9c ("regulator: core: Ensure we are at least in
bounds for our constraints") the imx53-qsb board populated with a Dialog
DA9053 PMIC fails to boot:

LDO3: Bringing 3300000uV into 1800000-1800000uV

The LDO3 voltage constraints passed in the device tree do not match
the valid range according to the datasheet, so fix this accordingly to
allow the board booting again.

While at it, fix the other voltage constraints as well.

Cc: <stable@vger.kernel.org> # 4.7.x
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
---
Changes since v1:
- Mention the commit that causes the issue

 arch/arm/boot/dts/imx53-qsb.dts | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/arm/boot/dts/imx53-qsb.dts b/arch/arm/boot/dts/imx53-qsb.dts
index dec4b07..3799396 100644
--- a/arch/arm/boot/dts/imx53-qsb.dts
+++ b/arch/arm/boot/dts/imx53-qsb.dts
@@ -64,8 +64,8 @@
 			};
 
 			ldo3_reg: ldo3 {
-				regulator-min-microvolt = <600000>;
-				regulator-max-microvolt = <1800000>;
+				regulator-min-microvolt = <1725000>;
+				regulator-max-microvolt = <3300000>;
 				regulator-always-on;
 			};
 
@@ -76,8 +76,8 @@
 			};
 
 			ldo5_reg: ldo5 {
-				regulator-min-microvolt = <1725000>;
-				regulator-max-microvolt = <3300000>;
+				regulator-min-microvolt = <1200000>;
+				regulator-max-microvolt = <3600000>;
 				regulator-always-on;
 			};
 
@@ -100,14 +100,14 @@
 			};
 
 			ldo9_reg: ldo9 {
-				regulator-min-microvolt = <1200000>;
+				regulator-min-microvolt = <1250000>;
 				regulator-max-microvolt = <3600000>;
 				regulator-always-on;
 			};
 
 			ldo10_reg: ldo10 {
-				regulator-min-microvolt = <1250000>;
-				regulator-max-microvolt = <3650000>;
+				regulator-min-microvolt = <1200000>;
+				regulator-max-microvolt = <3600000>;
 				regulator-always-on;
 			};
 		};
-- 
2.7.4

^ permalink raw reply related

* [PATCH v7, 0/8] Add MediaTek USB3 DRD Driver
From: Greg Kroah-Hartman @ 2016-10-27 15:05 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476844107-31087-1-git-send-email-chunfeng.yun@mediatek.com>

On Wed, Oct 19, 2016 at 10:28:19AM +0800, Chunfeng Yun wrote:
> These patches introduce the MediaTek USB3 dual-role controller
> driver.
> 
> The driver can be configured as Dual-Role Device (DRD),
> Peripheral Only and Host Only (xHCI) modes. It works well
> with Mass Storage, RNDIS and g_zero on FS/HS and SS. And it is
> tested on MT8173 platform which only contains USB2.0 device IP,
> and on MT6290 platform which contains USB3.0 device IP.
> 
> Change in v7:
> 1. split dual-role driver into four patchs
> 2. remove QMU done tasklet
> 3. add a bool in xhci_hcd_mtk to signal absence of IPPC

Given a lack of objection from anyone, I've now merged these to my tree
to get them a spin in the 0-day build-bot.

thanks,

greg k-h

^ permalink raw reply

* [SPAM][PATCH 2/3] irqchip: mtk-cirq: Add mediatek mtk-cirq implement
From: Yingjoe Chen @ 2016-10-27 15:02 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <1476335194-26604-3-git-send-email-youlin.pei@mediatek.com>

On Thu, 2016-10-13 at 13:06 +0800, Youlin Pei wrote:
> This commit add the mtk-cirq implement for mt2701.
> 
> Signed-off-by: Youlin Pei <youlin.pei@mediatek.com>
> ---
>  drivers/irqchip/Makefile       |    2 +-
>  drivers/irqchip/irq-mtk-cirq.c |  257 ++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 258 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/irqchip/irq-mtk-cirq.c
> 
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 4c203b6..eee95c6 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -59,7 +59,7 @@ obj-$(CONFIG_BCM7120_L2_IRQ)		+= irq-bcm7120-l2.o
>  obj-$(CONFIG_BRCMSTB_L2_IRQ)		+= irq-brcmstb-l2.o
>  obj-$(CONFIG_KEYSTONE_IRQ)		+= irq-keystone.o
>  obj-$(CONFIG_MIPS_GIC)			+= irq-mips-gic.o
> -obj-$(CONFIG_ARCH_MEDIATEK)		+= irq-mtk-sysirq.o
> +obj-$(CONFIG_ARCH_MEDIATEK)		+= irq-mtk-sysirq.o irq-mtk-cirq.o
>  obj-$(CONFIG_ARCH_DIGICOLOR)		+= irq-digicolor.o
>  obj-$(CONFIG_RENESAS_H8300H_INTC)	+= irq-renesas-h8300h.o
>  obj-$(CONFIG_RENESAS_H8S_INTC)		+= irq-renesas-h8s.o
> diff --git a/drivers/irqchip/irq-mtk-cirq.c b/drivers/irqchip/irq-mtk-cirq.c
> new file mode 100644
> index 0000000..544767d
> --- /dev/null
> +++ b/drivers/irqchip/irq-mtk-cirq.c
> @@ -0,0 +1,257 @@
> +/*
> + * Copyright (c) 2016 MediaTek Inc.
> + * Author: Youlin.Pei <youlin.pei@mediatek.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/irq.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqdomain.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_address.h>
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +#include <linux/syscore_ops.h>
> +
> +#define CIRQ_MASK_SET	0xC0
> +#define CIRQ_MASK_CLR	0x100
> +#define CIRQ_SENS_SET	0x180
> +#define CIRQ_SENS_CLR	0x1C0

nit: please use lower case for hex value

> +#define CIRQ_POL_SET	0x240
> +#define CIRQ_POL_CLR	0x280
> +#define CIRQ_CONTROL	0x300
> +
> +#define CIRQ_EN		0x1

nit: please align

> +#define CIRQ_EDGE	0x2
> +#define CIRQ_FLUSH	0x4
> +
> +#define CIRQ_IRQ_NUM    0x200
> +
> +struct mtk_cirq_chip_data {
> +	void __iomem *base;
> +	unsigned int ext_irq_start;
> +};
> +

<deleted..>

> +
> +static int __init mtk_cirq_of_init(struct device_node *node,
> +				   struct device_node *parent)
> +{
> +	struct irq_domain *domain, *domain_parent;
> +	int ret;
> +
> +	domain_parent = irq_find_host(parent);
> +	if (!domain_parent) {
> +		pr_err("mtk_cirq: interrupt-parent not found\n");
> +		return -EINVAL;
> +	}
> +
> +	cirq_data = kzalloc(sizeof(*cirq_data), GFP_KERNEL);
> +	if (!cirq_data)
> +		return -ENOMEM;
> +
> +	cirq_data->base = of_iomap(node, 0);
> +	if (!cirq_data->base) {
> +		pr_err("mtk_cirq: unable to map cirq register\n");
> +		ret = -ENXIO;
> +		goto out_free;
> +	}
> +
> +	if (of_property_read_u32(node, "mediatek,ext-irq-start",
> +				 &cirq_data->ext_irq_start)) {
> +		ret = -EINVAL;
> +		goto out_free;

Please propagate error returned from of_property_read_u32
Should goto out_unmap when fail here.

Joe.C

> +	}
> +
> +	domain = irq_domain_add_hierarchy(domain_parent, 0, CIRQ_IRQ_NUM, node,
> +					  &cirq_domain_ops, cirq_data);
> +	if (!domain) {
> +		ret = -ENOMEM;
> +		goto out_unmap;
> +	}
> +
> +	mtk_cirq_syscore_init();
> +
> +	return 0;
> +
> +out_unmap:
> +	iounmap(cirq_data->base);
> +out_free:
> +	kfree(cirq_data);
> +	return ret;
> +}
> +
> +IRQCHIP_DECLARE(mtk_cirq, "mediatek,mt2701-cirq", mtk_cirq_of_init);

^ permalink raw reply

* [RFC PATCH 1/5] of: introduce the overlay manager
From: Pantelis Antoniou @ 2016-10-27 14:56 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20161026145756.21689-2-antoine.tenart@free-electrons.com>

Hi Antoine,

> On Oct 26, 2016, at 17:57 , Antoine Tenart <antoine.tenart@free-electrons.com> wrote:
> 
> The overlay manager is an in-kernel library helping to handle dt overlay
> loading when using capes.
> 

All in all a nice idea. Comments inline.

> Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
> ---
> drivers/of/Kconfig                           |   2 +
> drivers/of/Makefile                          |   1 +
> drivers/of/overlay-manager/Kconfig           |   6 +
> drivers/of/overlay-manager/Makefile          |   1 +
> drivers/of/overlay-manager/overlay-manager.c | 199 +++++++++++++++++++++++++++
> include/linux/overlay-manager.h              |  38 +++++
> 6 files changed, 247 insertions(+)
> create mode 100644 drivers/of/overlay-manager/Kconfig
> create mode 100644 drivers/of/overlay-manager/Makefile
> create mode 100644 drivers/of/overlay-manager/overlay-manager.c
> create mode 100644 include/linux/overlay-manager.h
> 
> diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
> index bc07ad30c9bf..e57aeaf0bf4f 100644
> --- a/drivers/of/Kconfig
> +++ b/drivers/of/Kconfig
> @@ -116,4 +116,6 @@ config OF_OVERLAY
> config OF_NUMA
> 	bool
> 
> +source "drivers/of/overlay-manager/Kconfig"
> +
> endif # OF
> diff --git a/drivers/of/Makefile b/drivers/of/Makefile
> index d7efd9d458aa..d738fd41271f 100644
> --- a/drivers/of/Makefile
> +++ b/drivers/of/Makefile
> @@ -16,3 +16,4 @@ obj-$(CONFIG_OF_OVERLAY) += overlay.o
> obj-$(CONFIG_OF_NUMA) += of_numa.o
> 
> obj-$(CONFIG_OF_UNITTEST) += unittest-data/
> +obj-y += overlay-manager/
> diff --git a/drivers/of/overlay-manager/Kconfig b/drivers/of/overlay-manager/Kconfig
> new file mode 100644
> index 000000000000..eeb76054dcb8
> --- /dev/null
> +++ b/drivers/of/overlay-manager/Kconfig
> @@ -0,0 +1,6 @@
> +config OF_OVERLAY_MGR
> +	bool "Device Tree Overlay Manager"
> +	depends on OF_OVERLAY
> +	help
> +	  Enable the overlay manager to handle automatic overlay loading when
> +	  devices are detected.
> diff --git a/drivers/of/overlay-manager/Makefile b/drivers/of/overlay-manager/Makefile
> new file mode 100644
> index 000000000000..86d2b53950e7
> --- /dev/null
> +++ b/drivers/of/overlay-manager/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_OF_OVERLAY_MGR)			+= overlay-manager.o
> diff --git a/drivers/of/overlay-manager/overlay-manager.c b/drivers/of/overlay-manager/overlay-manager.c
> new file mode 100644
> index 000000000000..a725d7e24d38
> --- /dev/null
> +++ b/drivers/of/overlay-manager/overlay-manager.c
> @@ -0,0 +1,199 @@
> +/*
> + * Copyright (C) 2016 - Antoine Tenart <antoine.tenart@free-electrons.com>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/firmware.h>
> +#include <linux/list.h>
> +#include <linux/of.h>
> +#include <linux/of_fdt.h>
> +#include <linux/overlay-manager.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +
> +struct overlay_mgr_overlay {
> +	struct list_head list;
> +	char *name;
> +};
> +
> +LIST_HEAD(overlay_mgr_overlays);
> +LIST_HEAD(overlay_mgr_formats);
> +DEFINE_SPINLOCK(overlay_mgr_lock);
> +DEFINE_SPINLOCK(overlay_mgr_format_lock);
> +
> +/*
> + * overlay_mgr_register_format()
> + *
> + * Adds a new format candidate to the list of supported formats. The registered
> + * formats are used to parse the headers stored on the dips.
> + */
> +int overlay_mgr_register_format(struct overlay_mgr_format *candidate)
> +{
> +	struct overlay_mgr_format *format;
> +	int err = 0;
> +
> +	spin_lock(&overlay_mgr_format_lock);
> +
> +	/* Check if the format is already registered */
> +	list_for_each_entry(format, &overlay_mgr_formats, list) {
> +		if (!strcpy(format->name, candidate->name)) {
> +			err = -EEXIST;
> +			goto err;
> +		}
> +	}
> +
> +	list_add_tail(&candidate->list, &overlay_mgr_formats);
> +
> +err:
> +	spin_unlock(&overlay_mgr_format_lock);
> +	return err;
> +}
> +EXPORT_SYMBOL_GPL(overlay_mgr_register_format);
> +
> +/*
> + * overlay_mgr_parse()
> + *
> + * Parse raw data with registered format parsers. Fills the candidate string if
> + * one parser understood the raw data format.
> + */
> +int overlay_mgr_parse(struct device *dev, void *data, char ***candidates,
> +		      unsigned *n)
> +{
> +	struct list_head *pos, *tmp;
> +	struct overlay_mgr_format *format;
> +
> +	list_for_each_safe(pos, tmp, &overlay_mgr_formats) {
> +		format = list_entry(pos, struct overlay_mgr_format, list);
> +
> +		format->parse(dev, data, candidates, n);
> +		if (n > 0)
> +			return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(overlay_mgr_parse);
> +
> +static int overlay_mgr_check_overlay(struct device_node *node)
> +{
> +	struct property *p;
> +	const char *str = NULL;
> +
> +	p = of_find_property(node, "compatible", NULL);
> +	if (!p)
> +		return -EINVAL;
> +
> +	do {
> +		str = of_prop_next_string(p, str);
> +		if (of_machine_is_compatible(str))
> +			return 0;
> +	} while (str);
> +
> +	return -EINVAL;
> +}
> +
> +/*
> + * _overlay_mgr_insert()
> + *
> + * Try to request and apply an overlay given a candidate name.
> + */
> +static int _overlay_mgr_apply(struct device *dev, char *candidate)
> +{
> +	struct overlay_mgr_overlay *overlay;
> +	struct device_node *node;
> +	const struct firmware *firmware;
> +	char *firmware_name;
> +	int err = 0;
> +
> +	spin_lock(&overlay_mgr_lock);
> +
> +	list_for_each_entry(overlay, &overlay_mgr_overlays, list) {
> +		if (!strcmp(overlay->name, candidate)) {
> +			dev_err(dev, "overlay already loaded\n");
> +			err = -EEXIST;
> +			goto err_lock;
> +		}
> +	}
> +
> +	overlay = devm_kzalloc(dev, sizeof(*overlay), GFP_KERNEL);
> +	if (!overlay) {
> +		err = -ENOMEM;
> +		goto err_lock;
> +	}
> +
> +	overlay->name = candidate;
> +
> +	firmware_name = kasprintf(GFP_KERNEL, "overlay-%s.dtbo", candidate);
> +	if (!firmware_name) {
> +		err = -ENOMEM;
> +		goto err_free;
> +	}
> +
> +	dev_info(dev, "requesting firmware '%s'\n", firmware_name);
> +
> +	err = request_firmware_direct(&firmware, firmware_name, dev);
> +	if (err) {
> +		dev_info(dev, "failed to request firmware '%s'\n",
> +			 firmware_name);
> +		goto err_free;
> +	}
> +
> +	of_fdt_unflatten_tree((unsigned long *)firmware->data, NULL, &node);
> +	if (!node) {
> +		dev_err(dev, "failed to unflatted tree\n");
> +		err = -EINVAL;
> +		goto err_fw;
> +	}
> +
> +	of_node_set_flag(node, OF_DETACHED);
> +
> +	err = of_resolve_phandles(node);
> +	if (err) {
> +		dev_err(dev, "failed to resolve phandles: %d\n", err);
> +		goto err_fw;
> +	}
> +
> +	err = overlay_mgr_check_overlay(node);
> +	if (err) {
> +		dev_err(dev, "overlay checks failed: %d\n", err);
> +		goto err_fw;
> +	}
> +
> +	err = of_overlay_create(node);
> +	if (err < 0) {
> +		dev_err(dev, "failed to create overlay: %d\n", err);
> +		goto err_fw;
> +	}
> +
> +	list_add_tail(&overlay->list, &overlay_mgr_overlays);
> +
> +	dev_info(dev, "loaded firmware '%s'\n", firmware_name);
> +
> +	spin_unlock(&overlay_mgr_lock);
> +	return 0;
> +
> +err_fw:
> +	release_firmware(firmware);
> +err_free:
> +	devm_kfree(dev, overlay);
> +err_lock:
> +	spin_unlock(&overlay_mgr_lock);
> +	return err;
> +}
> +
> +int overlay_mgr_apply(struct device *dev, char **candidates, unsigned n)
> +{
> +	int i, ret;
> +
> +	for (i=0; i < n; i++) {
> +		ret = _overlay_mgr_apply(dev, candidates[i]);
> +		if (!ret)
> +			return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(overlay_mgr_apply);
> diff --git a/include/linux/overlay-manager.h b/include/linux/overlay-manager.h
> new file mode 100644
> index 000000000000..8adcc4f5ddf6
> --- /dev/null
> +++ b/include/linux/overlay-manager.h
> @@ -0,0 +1,38 @@
> +/*
> + * Copyright (C) 2016 - Antoine Tenart <antoine.tenart@free-electrons.com>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#ifndef __OVERLAY_MGR_H__
> +#define __OVERLAY_MGR_H__
> +
> +#include <linux/device.h>
> +#include <linux/list.h>
> +#include <linux/sizes.h>
> +
> +#define OVERLAY_MGR_DIP_MAX_SZ		SZ_128
> +


This should not be here; if it?s general kernel plumbing no mention to
specific boards/archs are relevant.


> +struct overlay_mgr_format {
> +	struct list_head list;
> +	char *name;
> +	int (*parse)(struct device *dev, void *data, char ***candidates,
> +		     unsigned *n);
> +};
> +
> +int overlay_mgr_register_format(struct overlay_mgr_format *candidate);
> +int overlay_mgr_parse(struct device *dev, void *data, char ***candidates,
> +		      unsigned *n);
> +int overlay_mgr_apply(struct device *dev, char **candidates, unsigned n);
> +
> +#define dip_convert(field)                                      \
> +        (                                                       \
> +                (sizeof(field) == 1) ? field :                  \
> +                (sizeof(field) == 2) ? be16_to_cpu(field) :     \
> +                (sizeof(field) == 4) ? be32_to_cpu(field) :     \
> +                -1                                              \
> +        )
> +

Same as above.

> +#endif /* __OVERLAY_MGR_H__ */
> -- 
> 2.10.1

Regards

? Pantelis

^ permalink raw reply

* [kernel-hardening] Re: [PATCH v3 0/7] arm64: Privileged Access Never using TTBR0_EL1 switching
From: Catalin Marinas @ 2016-10-27 14:54 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <CAGXu5jKEpZgc9zqmX=QKs_NH70fX_4CRNEtFKXEETK6UwykNMw@mail.gmail.com>

On Fri, Sep 30, 2016 at 11:42:02AM -0700, Kees Cook wrote:
> On Thu, Sep 29, 2016 at 3:44 PM, Sami Tolvanen <samitolvanen@google.com> wrote:
> > On Thu, Sep 15, 2016 at 05:20:45PM +0100, Mark Rutland wrote:
> >> Likewise, how do we handle __flush_cache_user_range and
> >> flush_icache_range? Some callers (e.g. __do_compat_cache_op) pass in
> >> __user addresses.
> >
> > Also EXEC_USERSPACE in lkdtm passes a user space address to flush_icache_range
> > and causes the process to hang when I tested these patches on HiKey.
> >
> > Adding uaccess_{enable,disable}_not_uao to __flush_cache_user_range appears to
> > fix the problem.
> 
> I had a thought just now on this: is lkdtm maybe doing the wrong thing
> here? i.e. should lkdtm be the one do to the uaccess_en/disable
> instead of flush_icache_range() itself, since it's the one abusing the
> API?

(preparing the v4 series)

I think lkdtm is using the API incorrectly here. The documentation for
flush_icache_range() (Documentation/cachetlb.txt) states that it is to
be used on kernel addresses. Even with uaccess_enable/disable in lkdtm,
faults on user space can still happen and the flush_icache_range()
function must be able to handle them. It happens to work on arm64
because of the fall through __flush_cache_user_range() but that's not
guaranteed on other architectures.

A potential solution is to use access_process_vm() and let the arch code
handle the cache maintenance automatically:

---------------------8<--------------------------------
>From fcbb7c9c30daf9bfc2a215ec10dba79c109ab835 Mon Sep 17 00:00:00 2001
From: Catalin Marinas <catalin.marinas@arm.com>
Date: Thu, 27 Oct 2016 15:47:20 +0100
Subject: [PATCH] lkdtm: Do not use flush_icache_range() on user addresses

The flush_icache_range() API is meant to be used on kernel addresses
only as it may not have the infrastructure (exception entries) to handle
user memory faults.

The lkdtm execute_user_location() function tests the kernel execution of
user space addresses by mmap'ing an anonymous page, copying some code
together with cache maintenance and attempting to run it. However, the
cache maintenance step may fail because of the incorrect API usage
described above. The patch changes lkdtm to use access_process_vm() for
copying the code into user space which would take care of the necessary
cache maintenance.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
 drivers/misc/lkdtm_perms.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/lkdtm_perms.c b/drivers/misc/lkdtm_perms.c
index 45f1c0f96612..c7635a79341f 100644
--- a/drivers/misc/lkdtm_perms.c
+++ b/drivers/misc/lkdtm_perms.c
@@ -60,15 +60,18 @@ static noinline void execute_location(void *dst, bool write)
 
 static void execute_user_location(void *dst)
 {
+	int copied;
+
 	/* Intentionally crossing kernel/user memory boundary. */
 	void (*func)(void) = dst;
 
 	pr_info("attempting ok execution at %p\n", do_nothing);
 	do_nothing();
 
-	if (copy_to_user((void __user *)dst, do_nothing, EXEC_SIZE))
+	copied = access_process_vm(current, (unsigned long)dst, do_nothing,
+				   EXEC_SIZE, FOLL_WRITE);
+	if (copied < EXEC_SIZE)
 		return;
-	flush_icache_range((unsigned long)dst, (unsigned long)dst + EXEC_SIZE);
 	pr_info("attempting bad execution@%p\n", func);
 	func();
 }

^ permalink raw reply related

* [PATCH v3] drivers: psci: PSCI checker module
From: Paul E. McKenney @ 2016-10-27 14:54 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <a3fd021e-1fae-08e3-994b-87efcf11b164@arm.com>

On Thu, Oct 27, 2016 at 01:51:57PM +0100, Kevin Brodsky wrote:
> On 27/10/16 10:13, Lorenzo Pieralisi wrote:
> >On Wed, Oct 26, 2016 at 11:11:48AM -0700, Paul E. McKenney wrote:
> >>On Wed, Oct 26, 2016 at 06:35:34PM +0100, Lorenzo Pieralisi wrote:
> >>>On Wed, Oct 26, 2016 at 10:22:52AM -0700, Paul E. McKenney wrote:
> >>>>On Wed, Oct 26, 2016 at 06:10:06PM +0100, Lorenzo Pieralisi wrote:
> >>[ . . . ]
> >>
> >>>>>Thanks a lot for your feedback, thoughts appreciated.
> >>>>Let me ask the question more directly.
> >>>>
> >>>>Why on earth are we trying to run these tests concurrently?
> >>>We must prevent that, no question about that, that's why I started
> >>>this discussion. It is not fine to enable this checker and the
> >>>RCU/LOCK torture hotplug tests at the same time.
> >>>
> >>>>After all, if we just run one at a time in isolation, there is no
> >>>>problem.
> >>>Fine by me, it was to understand if the current assumptions we made
> >>>are correct and they are definitely not. If we enable the PSCI checker
> >>>we must disable the torture rcu/lock hotplug tests either statically or
> >>>dynamically.
> >>What rcutorture, locktorture, and rcuperf do is to invoke
> >>torture_init_begin(), which returns false if one of these tests
> >>is already running.
> >>
> >>Perhaps we should extract this torture-test-exclusion and require
> >>than conflicting torture tests invoke it?
> >Yes if it can be extracted as a check (but it should also prevent the
> >torture tests from running and vice versa), either that or Kconfig
> >dependency (which we could do as a first step, waiting to add the
> >required interface to the torture test code ?).
> >
> >Thanks !
> >Lorenzo
> 
> That sounds like a reasonable idea, but then that would mean that the PSCI checker
> would have to wait until the torture test is finished if it is already running (and
> the other way around).
> 
> I wasn't aware that torture tests were hotplugging CPUs. I think that the most
> sensible thing to do right now is to make CONFIG_PSCI_CHECKER depend on
> !CONFIG_TORTURE_TEST (or maybe specifically !CONFIG_RCU_TORTURE_TEST &&
> !CONFIG_LOCK_TORTURE_TEST). We can try to make them work together afterwards, but for
> the sake of getting this patch merged in a reasonable amount of time, I think we
> should just exclude the conflicting tests at the build level in this patch. I'll also
> update the comment accordingly.

I suggest !CONFIG_TORTURE_TEST, given that there are a couple of other
tests in the offing.

							Thanx, Paul

> Thanks,
> Kevin
> IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> 

^ permalink raw reply

* [RFC PATCH 1/5] of: introduce the overlay manager
From: Antoine Tenart @ 2016-10-27 14:54 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <CANLsYkxF4_fZwaBe+_0twMhND3TfpnmkXA_1q=AN_j9=cQ5ukw@mail.gmail.com>

On Thu, Oct 27, 2016 at 08:49:29AM -0600, Mathieu Poirier wrote:
> 
> I agree - something like this should have attracted more reviews.  I
> suggest providing a better explanation, i.e what you are doing and why
> in more details.  I reviewed your set and I'm still not sure of
> exactly what it does, hence not being able to comment on the validity
> of the approach.
> 
> I'm pretty sure there is value in what you are suggesting, it's a
> matter of getting people to understand the approach and motivation.

That's what I tried to do in the cover-letter. What do you think is
missing that I should add in it?

Thanks,

Antoine

-- 
Antoine T?nart, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 801 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20161027/6ba52130/attachment-0001.sig>

^ permalink raw reply

* Add Allwinner Q8 tablets hardware manager
From: Hans de Goede @ 2016-10-27 14:53 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <CAJ-oXjTfRDvSKs9zZBxt1V2MR5C+XnsqfZBRTWwRrJXx-_7r=Q@mail.gmail.com>

Hi,

On 27-10-16 14:57, Pierre-Hugues Husson wrote:
> 2016-10-27 11:14 GMT+02:00 Hans de Goede <hdegoede@redhat.com>:
>> In my experience with these cheap boards, there is a mix of auto-probing +
>> device / revision specific os-image modifications. I keep coming back to
>> the touchscreen controller firmware (but also the orientation), for the
>> gsl1680 controller I need at least 2 different firmware files (per gsl1680
>> revision) to make all q8 tablets I have working. This is simply not solved
>> by the vendor android code, they just shove the right firmware into the
>> os-image. Likewise for the touchscreen orientation (x-mirored, y-mirored,
>> etc) too is just a hard-coded setting in the os-image.
> Reading your patch, it looks like to handle the two different firmware
> files, you're simply adding a command-line switch, there is no
> detection involved.
> Am I understanding correctly?

No, the firmware-name (and matching resolution as different firmwares
report different axis-ranges for the same digitizer) is selected
primarily by the touchscreen_variant which sets: touchscreen_fw_name,
touchscreen_width and touchscreen_height.

The touchscreen_variant module option defaults to -1 which means "auto",
when it is auto it gets set based on the touchscreen / accelerometer
combination (which more or less uniquely identifies boards sofar),
likewise all the other touchscreen module options default to -1,
but can be overridden from the commandline.

The intention is for things to just work, the commandline options are
there as a fallback.

> If this is the case, two things:
> 1. I'm not too sure having the user choose this via cmdline is the
> right way. I think I'd rather have it set by userspace. (though that's
> not a strong opinion).
> Or if cmdline is being changed... how about having DTS (or just an
> overlay on top of it) being changed instead?
>
> 2. This could still be declared by DTS. For instance, assuming your
> i2c-probe-stop-at-first-match:
> &i2c0 {
>         touchscreen1: gsl1680 at 40 {
>                 reg = <0x40>;
>                 compatible = "silead,gsl1680";
>                 enable-gpios = <&pio 7 1 GPIO_ACTIVE_HIGH>; /* PH1 */
>                 touchscreen-size = <1024 600>;
>                 touchscreen-fw = "gsl1680-a082-q8-700.fw";
>                 filter-names = "touchscreen_variant";
>                 filter-0 = "none", "gsl1680-a082-q8-700";
>                 id = <0xa0820000>;
>                 status = "disabled";
>         };
>         touchscreen2: gsl1680 at 40 {
>                 reg = <0x40>;
>                 compatible = "silead,gsl1680";
>                 enable-gpios = <&pio 7 1 GPIO_ACTIVE_HIGH>; /* PH1 */
>                 touchscreen-size = <480 800>;
>                 touchscreen-fw = "gsl1680-a082-q8-a70.fw";
>                 filter-names = "touchscreen_variant";
>                 filter-0 = "gsl1680-a082-q8-a70";
>                 id = <0xa0820000>;
>                status = "disabled";
>         };
>         touchscreen2: gsl1680 at 40 {
>                 reg = <0x40>;
>                 compatible = "silead,gsl1680";
>                 enable-gpios = <&pio 7 1 GPIO_ACTIVE_HIGH>; /* PH1 */
>                 touchscreen-size = <960 640>;
>                 touchscreen-fw = "gsl1680-b482-q8-d702.fw";
>                 filter-names = "touchscreen_variant";
>                 filter-0 = "gsl1680-b482-q8-d702";
>                 id = <0xb4820000>;
>                status = "disabled";
>         };
>         i2c-probe-stop-at-first-match = <&touchscreen1>,
> <&touchscreen2>, <&touchscreen3>;
> }
>
> With "none" value being the value when the "touchscreen_variant"
> option is not defined in cmdline.
>
> Please note that I'm not too sure whether SILEAD_REG_ID represents an
> OTP which can be changed by OEM, or if it's more of a hardware
> revision. Depending on this, this would either fit into a id =
> <0xa0820000> DTS line, or a compatible = "silead,gsl1680_a082",
> "silead,gsl1680"; DTS line.
>
>> Sofar I've only seen this with one type of touchscreen so an easy cop-out
>> would be to add an "optional-vddio-supply" to the the bindings for the
>> specific touchscreen use and put all the necessary logic in the driver.
>>
>> This does require propagating the learned need for the regulator
>> from the drivers detect() callback to probe() or alternatively I'm
>> thinking we should just use probe() instead of detect()to begin with,
>> that will save a lot of duplication with things
>> like code for enable gpio-s and regulators.
>>
>> So assuming we go for the cop-out option for 3. (I'm ok with that),
>> this would be a pretty clean solution adding just the 2 new:
>> i2c-probe-stop-at-first-match and i2c-probe-all properties to
>> the i2c-bus bindings. One problem here is that we may want to have
>> multiple i2c-probe-stop-at-first-match phandle lists on a single bus
>> (e.g. try 3 touchscreens + 6 accelerometers on the same bus, stop at
>> first touchscreen / first accelerometer), anyone have any ideas for
>> that?
> How about something like:
>
> &i2c1 {
>     touchscreen1....
>     touchscreen2....
>     touchscreen3....
>     accelerometer1....
>     accelerometer2....
>     accelerometer3....
>     accelerometer4....
>
>     select-one {
>        compatible = "i2c-select;
>        group-names = "touchscreen", "accelerometer";
>        group-0 = <&touchscreen1>, <&touchscreen2>, <&touchscreen3>;
>        group-1 = <&accelerometer1>, <&accelerometer2>,
> <&accelerometer3>, <&accelerometer4>;
>     };
> };

We could just have:

	i2c-probe-stop-at-first-match-0 = <&touchscreen1>, <&touchscreen2>, <&touchscreen3>;
	i2c-probe-stop-at-first-match-1 = <&accelerometer1>, <&accelerometer2>;

And have the i2c bus code look for an i2c-probe-stop-at-first-match-[i++] property
until it is not found. Having a child-node with its own compatible for this
feels wrong, as it uses a hierarchy where there really is none.

>>> When it comes to detection, I've witnessed various things.
>>> It can be kernel-side or bootloader-side "global setting" reading (like an
>>> ADC/resistor value, or an OTP), it can be bootloader doing the
>>> "brute-force", or it can be the kernel doing all the probes.
>>>
>>> For instance, as of today, on a Spreadtrum ODM tree, the bootloader will
>>> detect the screen by testing all knowns screens, the screen-drivers declare
>>> a get_id function, and the bootloader probes until the get_id matches the id
>>> declared by the screen driver.
>>> And then the bootloader tells the kernel, via cmdline, which screen is
>>> actually there (but auto-detection is also coded in kernel).
>>> Finally all possible sensors/touchscreen/camera are declared in DTS, and
>>> probe will filter-out N/C ones in the kernel.
>>>
>>> Now the big difference between my experience and what Hans is trying to
>>> do, is that I've always worked with devices with "safely" queriable IDs,
>>> either on i2c or dsi. I've never encountered SPI. This makes probing
>>> inherently more dangerous, but I believe the question roughly remains the
>>> same.
>>
>>
>> I'm dealing with i2c too, Mark mistakenly used SPI in his reply,
>> which I think is what got you thinking I've SPI.
> Right, so let's concentrate on reasonable bus-es first then. (I can
> think of I2C and DSI)
>
>> See above, I think that we can make this work by delegating the actual
>> detection to the driver (so each compatible can have a different detect
>> method / code).
>> So with this we can remove a big part of drivers/misc/q8-hardwaremgr.c, but
>> not all
>> of it. We still need board specific code somewhere to deal with things like
>> picking
>> the right touchscreen firmware and touchscreen orientation. This is all
>> somewhat
>> gsl1680 specific.
>> I actually have the same problem on x86 where the ACPI description of the
>> device
>> basically says: "There is a gsl1680 at this bus at this address" and does
>> not say
>> anything about firmware / orientation (again this is simply hardcoded
>> in the os-image these devices ship with).
>>
>> For x86 my plan is to have an array of configs in the driver and select the
>> right
>> one based on DMI strings, which is in essence putting board specific info in
>> the
>> driver.
>>
>> I can imagine mirroring this for ARM, and have an array of configs in the
>> driver
>> there too (for cases where cannot simply hardcode everything in dt only) and
>> have
>> some board specific code (activated by of_machine_is_compatible()) to select
>> the
>> right config.
> I do believe this can all be done in DTS

Well x86 does not have DTS.

> and at the moment, what
> you're describing seem to happen often enough to be worth writing
> generic code for.

Let me quote some of the auto-code currently in q8-hardwaremgr.c :

                 /*
                  * These accelerometer based heuristics select the best
                  * default based on known q8 tablets.
                  */
                 switch (data->accelerometer.model) {
                 case da280:
                         if (data->accelerometer.addr == 0x27)
                                 ; /* No-op */
                         else if (data->has_rda599x)
                                 data->touchscreen_invert_x = 1;
                         else
                                 data->touchscreen_invert_y = 1;
                         break;
                 case dmard09:
                         data->touchscreen_invert_x = 1;
                         break;
                 case mxc6225:
                         data->touchscreen_variant = 1;
                         break;
                 }

(Non set data->touchscreen_foo are left at 0).

So this would require us to be able to filter (to use your example)
on if another i2c device is found and on which address it is found,
that does not even take the rda559x check into account and is
going to cause interesting ordering issues, how do we know when
we can actually do the filtering if some of the variables we are
filtering on are set by other auto-detected paths. Which auto-detect /
i2c-probe-stop-at-first-match list do we execute first ? Worse
actually for accelerometer orientation I will likely need to
set the mount-matrix based on the detected touchscreen ...

The rda559x here is a sdio wifi chip, which is also connected to the
i2c, and currently is detected through i2c to be able to separately
identify 2 q8 boards which share the same touchscreen + accelerometer
combination and who knows what other checks I or other people can
come up with to differentiate board variants which do not have
a simple eeprom to uniquely id them.

So as said before, no this cannot be all done in dt without
adding a turing complete language to dt, and that is just to
select which touchscreen_variant to use.

Then there also the probem of the combinatorial explosion having
not only 2 firmware files but also invert-x and invert-y flags causes:
We have 2 revisions with each 2 different firmware-files (more actually
but I've reduced the set since some firmwares are compatible) with each
both the x- and / or y axis as normal or inverted, for a total of:
2 (revision) * 2 (firmware-files) * 2 (x-inverted or not) * 2 (y...) = 16
touchscreen variants, which means dt nodes for touchscreen1 to touchscreen16
and that is just the silead gsl1680, some of these tablets also have
elan or zeitec touchscreen controllers.

Now imagine what happens if a new board comes out which needs a 3th firmware
file... I hope you can understand this is not a route I want to go.

Another problem is that if a user encounters the need for a new firmware
variant he can now not easily try this (where as before we had
module options to separately override firmware-name, the size, etc.

As written in my previous mail, this is all rather gsl1680 specific,
and esp. being able to override the firmware-name, the size, etc.
through module options is going to be useful (to ask endusers to test
stuff without recompiling) on x86 too. So we will likely want to add
most of the necessary stuff to the silead driver anyways.

> But then, I can't really tell which makes the most sense between
> source-based and devicetree-based.
> I prefer doing it in device-tree, since it means that any OEM can have
> his device supported by only providing DTB, and won't need to provide
> kernel patches.

If the OEM provides a DTB the OEM can just directly have the right
parameters in there without relying on any auto-detection, this is
already supported and the e.g. gsl1680 driver already happily
works on several tablets where there is not so much hardware
variance.

Even if the OEM needs to deal with e.g. different touchscreens on
different board revisions, hopefully the simple auto-detect code will
be enough, and he does not need e.g. different firmware-name settings
for otherwise the same touchscreen controller. If that is not the
case then he the OEM will have to provide a separate static
(non probing) DTB per variant.

>> 2) miscellaneous extra config on top of figuring out which ICs are
>> connected,
>> basically the kind of stuff many vendors simply hard-code in their device
>> specific os-image. This one is much more difficult to deal with and I think
>> we need to figure this out on a case by case basis. This will require board
>> specific code (just like the kernel has tons of DMI string activated board
>> specific code on x86) and what is the best code for this place to live will
>> be a case by case thing too.
>
> With things like mount-matrix devicetree property, the goal is to have
> such informations in the DTS.

Right and all the info I'm talking about can already be in the DTS and
is already specified this way for various existing boards, this is
obviously how we want things to work, this is the normal case /
the straight code path.

Now lets get back to your mount-matrix example, the problem here is 2 board
variants where the same accelerometer is used, but on a newer revision
of the board it is mounted with a different orientation and otherwise
almost nothing is changed on the board, certainly not something as
useful as an id eeprom.

Lets assume that we can however still somehow differ the 2 revisions,
then try to imagine how many different ways there are to differ
between 2 board revisions if there is no easy way to do so,
some crazy examples:
-The 2nd revision has an external loopback on unused audio out / in
  pins for testing purposes, we could play + record sound and do
  a (rough) waveform match to see if the loopback is present
-On the 2nd revision a pin from a pin compatible part which
  allows putting it in fully compatible mode, or allow new features
  mode, is now hooked up to a gpio instead of hardwired to compatible
  mode, we could change the device to new features mode and try
  to read/modify/write some register bit on the chip which is only
  writable in this mode
-Etc.

Now try to design a way to express this in dt and we're back to
needing a turing complete language (with a library for accessing
various busses) again.

Regards,

Hans

^ permalink raw reply

* [RFC PATCH 1/5] of: introduce the overlay manager
From: Mathieu Poirier @ 2016-10-27 14:49 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20161027140342.kidk4gqxwbtphrbs@kwain>

On 27 October 2016 at 08:03, Antoine Tenart
<antoine.tenart@free-electrons.com> wrote:
> Hello Mathieu,
>
> On Wed, Oct 26, 2016 at 10:29:59AM -0600, Mathieu Poirier wrote:
>>
>> Please find my comments below.
>
> Thanks for the comments. I expected more distant reviews, on the overall
> architecture to know if this could fit the needs of others. But anyway
> your comments are helpful if we ever decide to go with an overlay
> manager like this one.

I agree - something like this should have attracted more reviews.  I
suggest providing a better explanation, i.e what you are doing and why
in more details.  I reviewed your set and I'm still not sure of
exactly what it does, hence not being able to comment on the validity
of the approach.

I'm pretty sure there is value in what you are suggesting, it's a
matter of getting people to understand the approach and motivation.

>
>> On 26 October 2016 at 08:57, Antoine Tenart
>> <antoine.tenart@free-electrons.com> wrote:
>> > +
>> > +/*
>> > + * overlay_mgr_register_format()
>> > + *
>> > + * Adds a new format candidate to the list of supported formats. The registered
>> > + * formats are used to parse the headers stored on the dips.
>> > + */
>> > +int overlay_mgr_register_format(struct overlay_mgr_format *candidate)
>> > +{
>> > +       struct overlay_mgr_format *format;
>> > +       int err = 0;
>> > +
>> > +       spin_lock(&overlay_mgr_format_lock);
>> > +
>> > +       /* Check if the format is already registered */
>> > +       list_for_each_entry(format, &overlay_mgr_formats, list) {
>> > +               if (!strcpy(format->name, candidate->name)) {
>>
>> This function is public to the rest of the kernel - limiting the
>> lenght of ->name and using strncpy() is probably a good idea.
>
> I totally agree. This was in fact something I wanted to do.
>
>> > +
>> > +/*
>> > + * overlay_mgr_parse()
>> > + *
>> > + * Parse raw data with registered format parsers. Fills the candidate string if
>> > + * one parser understood the raw data format.
>> > + */
>> > +int overlay_mgr_parse(struct device *dev, void *data, char ***candidates,
>>
>> I'm pretty sure there is another way to proceed than using 3 levels of
>> references.  It makes the code hard to read and a prime candidate for
>> errors.
>
> Sure. I guess we could allocate an array of fixed-length strings which
> would be less flexible but I don't think we need something that flexible
> here.
>
>>
>> > +
>> > +               format->parse(dev, data, candidates, n);
>>
>> ->parse() returns an error code.  It is probably a good idea to check
>> it.  If it isn't needed then a comment explaining why it is the case
>> would be appreciated.
>
> So the point of the parse function is to determine if the data read from
> a source is a compatible header of a given format. Returning an error
> doesn't mean the header won't be recognized by another one.
>
> We could maybe handle this better, by returning an error iif different
> that -EINVAL. Or we could have one function to check the compatibility
> and one to parse it, if compatible.
>
>> > +static int _overlay_mgr_apply(struct device *dev, char *candidate)
>> > +{
>> > +       struct overlay_mgr_overlay *overlay;
>> > +       struct device_node *node;
>> > +       const struct firmware *firmware;
>> > +       char *firmware_name;
>> > +       int err = 0;
>> > +
>> > +       spin_lock(&overlay_mgr_lock);
>> > +
>> > +       list_for_each_entry(overlay, &overlay_mgr_overlays, list) {
>> > +               if (!strcmp(overlay->name, candidate)) {
>> > +                       dev_err(dev, "overlay already loaded\n");
>> > +                       err = -EEXIST;
>> > +                       goto err_lock;
>> > +               }
>> > +       }
>> > +
>> > +       overlay = devm_kzalloc(dev, sizeof(*overlay), GFP_KERNEL);
>>
>> Function devm_kzalloc() can sleep but you're holding a spinlock - I'm
>> surprised the kernel didn't complain here.  Allocate the memory before
>> holding the lock.  If the overly is already loaded simply free it on
>> the error path.
>
> Right.
>
> Thanks,
>
> Antoine
>
> --
> Antoine T?nart, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com

^ permalink raw reply

* [PATCH v3 2/3] drm: zte: add initial vou drm driver
From: Shawn Guo @ 2016-10-27 14:42 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <CAOw6vbKbdWJ8eJD3oXwPd6-ykaOu+QP6isqAz8HkjS0p+2wX=w@mail.gmail.com>

> On Thu, Oct 20, 2016 at 3:30 AM, Shawn Guo <shawn.guo@linaro.org> wrote:
> > It adds the initial ZTE VOU display controller DRM driver.  There are
> > still some features to be added, like overlay plane, scaling, and more
> > output devices support.  But it's already useful with dual CRTCs and
> > HDMI monitor working.
> >
> > Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

<snip>

> > +static int zx_drm_bind(struct device *dev)
> > +{
> > +       struct drm_device *drm;
> > +       struct zx_drm_private *priv;
> > +       int ret;
> > +
> > +       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> > +       if (!priv)
> > +               return -ENOMEM;
> > +
> > +       drm = drm_dev_alloc(&zx_drm_driver, dev);
> > +       if (!drm)
> > +               return -ENOMEM;
> > +
> > +       drm->dev_private = priv;
> > +       dev_set_drvdata(dev, drm);
> > +
> > +       drm_mode_config_init(drm);
> > +       drm->mode_config.min_width = 16;
> > +       drm->mode_config.min_height = 16;
> > +       drm->mode_config.max_width = 4096;
> > +       drm->mode_config.max_height = 4096;
> > +       drm->mode_config.funcs = &zx_drm_mode_config_funcs;
> > +
> > +       ret = component_bind_all(dev, drm);
> > +       if (ret) {
> > +               dev_err(dev, "failed to bind all components: %d\n", ret);
> 
> Consider using the new DRM_DEV_* messages instead of the plain old dev_*

Okay, I will switch to DRM_DEV_* for log messages.

> 
> > +               goto out_unregister;
> > +       }
> > +
> > +       ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
> > +       if (ret < 0) {
> > +               dev_err(dev, "failed to init vblank: %d\n", ret);
> > +               goto out_unbind;
> > +       }
> > +
> > +       /*
> > +        * We will manage irq handler on our own.  In this case, irq_enabled
> > +        * need to be true for using vblank core support.
> > +        */
> > +       drm->irq_enabled = true;
> > +
> > +       drm_mode_config_reset(drm);
> > +       drm_kms_helper_poll_init(drm);
> > +
> > +       priv->fbdev = drm_fbdev_cma_init(drm, 32, drm->mode_config.num_crtc,
> > +                                        drm->mode_config.num_connector);
> > +       if (IS_ERR(priv->fbdev)) {
> > +               ret = PTR_ERR(priv->fbdev);
> > +               dev_err(dev, "failed to init cma fbdev: %d\n", ret);
> > +               priv->fbdev = NULL;
> > +               goto out_poll_fini;
> > +       }
> > +
> > +       ret = drm_dev_register(drm, 0);
> > +       if (ret)
> > +               goto out_fbdev_fini;
> > +
> > +       return 0;
> > +
> > +out_fbdev_fini:
> > +       if (priv->fbdev) {
> > +               drm_fbdev_cma_fini(priv->fbdev);
> > +               priv->fbdev = NULL;
> > +       }
> > +out_poll_fini:
> > +       drm_kms_helper_poll_fini(drm);
> > +       drm_mode_config_cleanup(drm);
> > +       drm_vblank_cleanup(drm);
> > +out_unbind:
> > +       component_unbind_all(dev, drm);
> > +out_unregister:
> > +       dev_set_drvdata(dev, NULL);
> > +       drm->dev_private = NULL;
> > +       drm_dev_unref(drm);
> > +       return ret;
> > +}

<snip>

> > +static int zx_hdmi_i2c_read(struct zx_hdmi *hdmi, struct i2c_msg *msg)
> > +{
> > +       int len = msg->len;
> > +       u8 *buf = msg->buf;
> > +       int retry = 0;
> > +       int ret = 0;
> > +
> > +       /* Bits [9:8] of bytes */
> > +       hdmi_writeb(hdmi, ZX_DDC_DIN_CNT2, (len >> 8) & 0xff);
> > +       /* Bits [7:0] of bytes */
> > +       hdmi_writeb(hdmi, ZX_DDC_DIN_CNT1, len & 0xff);
> > +
> > +       /* Clear FIFO */
> > +       hdmi_writeb_mask(hdmi, ZX_DDC_CMD, DDC_CMD_MASK, DDC_CMD_CLEAR_FIFO);
> > +
> > +       /* Kick off the read */
> > +       hdmi_writeb_mask(hdmi, ZX_DDC_CMD, DDC_CMD_MASK,
> > +                        DDC_CMD_SEQUENTIAL_READ);
> > +
> > +       while (len > 0) {
> > +               int cnt, i;
> > +
> > +               /* FIFO needs some time to get ready */
> > +               usleep_range(500, 1000);
> > +
> > +               cnt = hdmi_readb(hdmi, ZX_DDC_DOUT_CNT) & DDC_DOUT_CNT_MASK;
> > +               if (cnt == 0) {
> > +                       if (++retry > 5) {
> > +                               dev_err(hdmi->dev, "DDC FIFO read timed out!");
> > +                               ret = -ETIMEDOUT;
> > +                               break;
> 
> Why not just return -ETIMEDOUT here?

Yes.  Stupid me.

> > +                       }
> > +                       continue;
> > +               }
> > +
> > +               for (i = 0; i < cnt; i++)
> > +                       *buf++ = hdmi_readb(hdmi, ZX_DDC_DATA);
> > +               len -= cnt;
> > +       }
> > +
> > +       return ret;
> > +}

<snip>

> > +static int zx_hdmi_bind(struct device *dev, struct device *master, void *data)
> > +{
> > +       struct platform_device *pdev = to_platform_device(dev);
> > +       struct drm_device *drm = data;
> > +       struct resource *res;
> > +       struct zx_hdmi *hdmi;
> > +       int irq;
> > +       int ret;
> > +
> > +       hdmi = devm_kzalloc(dev, sizeof(*hdmi), GFP_KERNEL);
> > +       if (!hdmi)
> > +               return -ENOMEM;
> > +
> > +       hdmi->dev = dev;
> > +       hdmi->drm = drm;
> > +       hdmi->inf = &vou_inf_hdmi;
> > +
> > +       dev_set_drvdata(dev, hdmi);
> > +
> > +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +       hdmi->mmio = devm_ioremap_resource(dev, res);
> > +       if (IS_ERR(hdmi->mmio)) {
> > +               ret = PTR_ERR(hdmi->mmio);
> > +               dev_err(dev, "failed to remap hdmi region: %d\n", ret);
> > +               return ret;
> > +       }
> > +
> > +       irq = platform_get_irq(pdev, 0);
> > +       if (irq < 0)
> > +               return irq;
> > +
> > +       hdmi->cec_clk = devm_clk_get(hdmi->dev, "osc_cec");
> > +       if (IS_ERR(hdmi->cec_clk)) {
> > +               ret = PTR_ERR(hdmi->cec_clk);
> > +               dev_err(dev, "failed to get cec_clk: %d\n", ret);
> > +               return ret;
> > +       }
> > +
> > +       hdmi->osc_clk = devm_clk_get(hdmi->dev, "osc_clk");
> > +       if (IS_ERR(hdmi->osc_clk)) {
> > +               ret = PTR_ERR(hdmi->osc_clk);
> > +               dev_err(dev, "failed to get osc_clk: %d\n", ret);
> > +               return ret;
> > +       }
> > +
> > +       hdmi->xclk = devm_clk_get(hdmi->dev, "xclk");
> > +       if (IS_ERR(hdmi->xclk)) {
> > +               ret = PTR_ERR(hdmi->xclk);
> > +               dev_err(dev, "failed to get xclk: %d\n", ret);
> > +               return ret;
> > +       }
> > +
> > +       zx_hdmi_hw_init(hdmi);
> > +
> > +       ret = clk_prepare_enable(hdmi->cec_clk);
> > +       if (ret) {
> > +               dev_err(dev, "failed to enable cec_clk: %d\n", ret);
> > +               return ret;
> > +       }
> > +
> > +       ret = clk_prepare_enable(hdmi->osc_clk);
> > +       if (ret) {
> > +               dev_err(dev, "failed to enable osc_clk: %d\n", ret);
> > +               goto disable_cec_clk;
> > +       }
> > +
> > +       ret = clk_prepare_enable(hdmi->xclk);
> > +       if (ret) {
> > +               dev_err(dev, "failed to enable xclk: %d\n", ret);
> > +               goto disable_osc_clk;
> > +       }
> 
> Perhaps add a TODO above hdmi_hw_init() to move it and the clock
> enables to .enable and conversely implement .disable?

Instead of leaving a TODO item there, I would like to change it right
away in the next version.

> > +
> > +
> > +       ret = zx_hdmi_ddc_register(hdmi);
> > +       if (ret) {
> > +               dev_err(dev, "failed to register ddc: %d\n", ret);
> > +               goto disable_xclk;
> > +       }
> > +
> > +       ret = zx_hdmi_register(drm, hdmi);
> > +       if (ret) {
> > +               dev_err(dev, "failed to register hdmi: %d\n", ret);
> > +               goto disable_xclk;
> > +       }
> > +
> > +       ret = devm_request_threaded_irq(dev, irq, zx_hdmi_irq_handler,
> > +                                       zx_hdmi_irq_thread, IRQF_SHARED,
> > +                                       dev_name(dev), hdmi);
> > +       if (ret) {
> > +               dev_err(dev, "failed to request threaded irq: %d\n", ret);
> > +               goto disable_xclk;
> > +       }
> > +
> > +       return 0;
> > +
> > +disable_xclk:
> > +       clk_disable_unprepare(hdmi->xclk);
> > +disable_osc_clk:
> > +       clk_disable_unprepare(hdmi->osc_clk);
> > +disable_cec_clk:
> > +       clk_disable_unprepare(hdmi->cec_clk);
> > +       return ret;
> > +}

<snip>

> > +static int zx_gl_plane_atomic_check(struct drm_plane *plane,
> > +                                   struct drm_plane_state *plane_state)
> > +{
> > +       struct drm_framebuffer *fb = plane_state->fb;
> > +       struct drm_crtc *crtc = plane_state->crtc;
> > +       struct drm_crtc_state *crtc_state;
> > +       struct drm_rect clip;
> > +
> > +       if (!crtc || !fb)
> > +               return 0;
> > +
> > +       crtc_state = drm_atomic_get_existing_crtc_state(plane_state->state,
> > +                                                       crtc);
> > +       if (WARN_ON(!crtc_state))
> > +               return -EINVAL;
> > +
> > +       /* plane must match crtc enable state */
> > +       if (crtc_state->enable != !!plane_state->crtc)
> > +               return -EINVAL;
> > +
> > +       /* nothing to check when disabling or disabled */
> > +       if (!crtc_state->enable)
> > +               return 0;
> 
> I think you can shuffle things around here to read a bit clearer:
> 
> if (!crtc_state->enable)
>         return 0;
> 
> if (!plane_state->crtc)
>         return -EINVAL

Indeed.

> > +
> > +       clip.x1 = 0;
> > +       clip.y1 = 0;
> > +       clip.x2 = crtc_state->adjusted_mode.hdisplay;
> > +       clip.y2 = crtc_state->adjusted_mode.vdisplay;
> > +
> > +       return drm_plane_helper_check_state(plane_state, &clip,
> > +                                           DRM_PLANE_HELPER_NO_SCALING,
> > +                                           DRM_PLANE_HELPER_NO_SCALING,
> > +                                           false, true);
> > +}

<snip>

> > +/* Sub-module offset */
> > +#define MAIN_GL_OFFSET                 0x130
> > +#define MAIN_CSC_OFFSET                        0x580
> > +#define MAIN_HBSC_OFFSET               0x820
> > +#define MAIN_RSZ_OFFSET                        0x600 /* OTFPPU sub-module */
> > +
> > +#define AUX_GL_OFFSET                  0x200
> > +#define AUX_CSC_OFFSET                 0x5d0
> > +#define AUX_HBSC_OFFSET                        0x860
> > +#define AUX_RSZ_OFFSET                 0x800
> > +
> > +/* OSD (GPC_GLOBAL) registers */
> > +#define OSD_INT_STA                    0x04
> > +#define OSD_INT_CLRSTA                 0x08
> > +#define OSD_INT_MSK                    0x0c
> > +#define OSD_INT_AUX_UPT                        BIT(14)
> > +#define OSD_INT_MAIN_UPT               BIT(13)
> > +#define OSD_INT_GL1_LBW                        BIT(10)
> > +#define OSD_INT_GL0_LBW                        BIT(9)
> > +#define OSD_INT_VL2_LBW                        BIT(8)
> > +#define OSD_INT_VL1_LBW                        BIT(7)
> > +#define OSD_INT_VL0_LBW                        BIT(6)
> > +#define OSD_INT_BUS_ERR                        BIT(3)
> > +#define OSD_INT_CFG_ERR                        BIT(2)
> > +#define OSD_INT_ERROR (\
> > +       OSD_INT_GL1_LBW | OSD_INT_GL0_LBW | \
> > +       OSD_INT_VL2_LBW | OSD_INT_VL1_LBW | OSD_INT_VL0_LBW | \
> > +       OSD_INT_BUS_ERR | OSD_INT_CFG_ERR \
> > +)
> > +#define OSD_INT_ENABLE (OSD_INT_ERROR | OSD_INT_AUX_UPT | OSD_INT_MAIN_UPT)
> > +#define OSD_CTRL0                      0x10
> > +#define OSD_CTRL0_GL0_EN               BIT(7)
> > +#define OSD_CTRL0_GL0_SEL              BIT(6)
> > +#define OSD_CTRL0_GL1_EN               BIT(5)
> > +#define OSD_CTRL0_GL1_SEL              BIT(4)
> > +#define OSD_RST_CLR                    0x1c
> > +#define RST_PER_FRAME                  BIT(19)
> > +
> > +/* Main/Aux channel registers */
> > +#define OSD_MAIN_CHN                   0x470
> > +#define OSD_AUX_CHN                    0x4d0
> > +#define CHN_CTRL0                      0x00
> > +#define CHN_ENABLE                     BIT(0)
> > +#define CHN_CTRL1                      0x04
> > +#define CHN_SCREEN_W_SHIFT             18
> > +#define CHN_SCREEN_W_MASK              (0x1fff << CHN_SCREEN_W_SHIFT)
> > +#define CHN_SCREEN_H_SHIFT             5
> > +#define CHN_SCREEN_H_MASK              (0x1fff << CHN_SCREEN_H_SHIFT)
> > +#define CHN_UPDATE                     0x08
> > +
> > +/* TIMING_CTRL registers */
> > +#define TIMING_TC_ENABLE               0x04
> > +#define AUX_TC_EN                      BIT(1)
> > +#define MAIN_TC_EN                     BIT(0)
> > +#define FIR_MAIN_ACTIVE                        0x08
> > +#define FIR_AUX_ACTIVE                 0x0c
> > +#define V_ACTIVE_SHIFT                 16
> > +#define V_ACTIVE_MASK                  (0xffff << V_ACTIVE_SHIFT)
> > +#define H_ACTIVE_SHIFT                 0
> > +#define H_ACTIVE_MASK                  (0xffff << H_ACTIVE_SHIFT)
> > +#define FIR_MAIN_H_TIMING              0x10
> > +#define FIR_MAIN_V_TIMING              0x14
> > +#define FIR_AUX_H_TIMING               0x18
> > +#define FIR_AUX_V_TIMING               0x1c
> > +#define SYNC_WIDE_SHIFT                        22
> > +#define SYNC_WIDE_MASK                 (0x3ff << SYNC_WIDE_SHIFT)
> > +#define BACK_PORCH_SHIFT               11
> > +#define BACK_PORCH_MASK                        (0x7ff << BACK_PORCH_SHIFT)
> > +#define FRONT_PORCH_SHIFT              0
> > +#define FRONT_PORCH_MASK               (0x7ff << FRONT_PORCH_SHIFT)
> > +#define TIMING_CTRL                    0x20
> > +#define AUX_POL_SHIFT                  3
> > +#define AUX_POL_MASK                   (0x7 << AUX_POL_SHIFT)
> > +#define MAIN_POL_SHIFT                 0
> > +#define MAIN_POL_MASK                  (0x7 << MAIN_POL_SHIFT)
> > +#define POL_DE_SHIFT                   2
> > +#define POL_VSYNC_SHIFT                        1
> > +#define POL_HSYNC_SHIFT                        0
> > +#define TIMING_INT_CTRL                        0x24
> > +#define TIMING_INT_STATE               0x28
> > +#define TIMING_INT_AUX_FRAME           BIT(3)
> > +#define TIMING_INT_MAIN_FRAME          BIT(1)
> > +#define TIMING_INT_AUX_FRAME_SEL_VSW   (0x2 << 10)
> > +#define TIMING_INT_MAIN_FRAME_SEL_VSW  (0x2 << 6)
> > +#define TIMING_INT_ENABLE (\
> > +       TIMING_INT_MAIN_FRAME_SEL_VSW | TIMING_INT_AUX_FRAME_SEL_VSW | \
> > +       TIMING_INT_MAIN_FRAME | TIMING_INT_AUX_FRAME \
> > +)
> > +#define TIMING_MAIN_SHIFT              0x2c
> > +#define TIMING_AUX_SHIFT               0x30
> > +#define H_SHIFT_VAL                    0x0048
> > +#define TIMING_MAIN_PI_SHIFT           0x68
> > +#define TIMING_AUX_PI_SHIFT            0x6c
> > +#define H_PI_SHIFT_VAL                 0x000f
> > +
> > +#define V_ACTIVE(x)    (((x) << V_ACTIVE_SHIFT) & V_ACTIVE_MASK)
> > +#define H_ACTIVE(x)    (((x) << H_ACTIVE_SHIFT) & H_ACTIVE_MASK)
> > +
> > +#define SYNC_WIDE(x)   (((x) << SYNC_WIDE_SHIFT) & SYNC_WIDE_MASK)
> > +#define BACK_PORCH(x)  (((x) << BACK_PORCH_SHIFT) & BACK_PORCH_MASK)
> > +#define FRONT_PORCH(x) (((x) << FRONT_PORCH_SHIFT) & FRONT_PORCH_MASK)
> > +
> > +/* DTRC registers */
> > +#define DTRC_F0_CTRL                   0x2c
> > +#define DTRC_F1_CTRL                   0x5c
> > +#define DTRC_DECOMPRESS_BYPASS         BIT(17)
> > +#define DTRC_DETILE_CTRL               0x68
> > +#define TILE2RASTESCAN_BYPASS_MODE     BIT(30)
> > +#define DETILE_ARIDR_MODE_MASK         (0x3 << 0)
> > +#define DETILE_ARID_ALL                        0
> > +#define DETILE_ARID_IN_ARIDR           1
> > +#define DETILE_ARID_BYP_BUT_ARIDR      2
> > +#define DETILE_ARID_IN_ARIDR2          3
> > +#define DTRC_ARID                      0x6c
> > +#define DTRC_ARID3_SHIFT               24
> > +#define DTRC_ARID3_MASK                        (0xff << DTRC_ARID3_SHIFT)
> > +#define DTRC_ARID2_SHIFT               16
> > +#define DTRC_ARID2_MASK                        (0xff << DTRC_ARID2_SHIFT)
> > +#define DTRC_ARID1_SHIFT               8
> > +#define DTRC_ARID1_MASK                        (0xff << DTRC_ARID1_SHIFT)
> > +#define DTRC_ARID0_SHIFT               0
> > +#define DTRC_ARID0_MASK                        (0xff << DTRC_ARID0_SHIFT)
> > +#define DTRC_DEC2DDR_ARID              0x70
> > +
> > +#define DTRC_ARID3(x)  (((x) << DTRC_ARID3_SHIFT) & DTRC_ARID3_MASK)
> > +#define DTRC_ARID2(x)  (((x) << DTRC_ARID2_SHIFT) & DTRC_ARID2_MASK)
> > +#define DTRC_ARID1(x)  (((x) << DTRC_ARID1_SHIFT) & DTRC_ARID1_MASK)
> > +#define DTRC_ARID0(x)  (((x) << DTRC_ARID0_SHIFT) & DTRC_ARID0_MASK)
> > +
> > +/* VOU_CTRL registers */
> > +#define VOU_INF_EN                     0x00
> > +#define VOU_INF_CH_SEL                 0x04
> > +#define VOU_INF_DATA_SEL               0x08
> > +#define VOU_SOFT_RST                   0x14
> > +#define VOU_CLK_SEL                    0x18
> > +#define VOU_CLK_GL1_SEL                        BIT(5)
> > +#define VOU_CLK_GL0_SEL                        BIT(4)
> > +#define VOU_CLK_REQEN                  0x20
> > +#define VOU_CLK_EN                     0x24
> > +
> > +/* OTFPPU_CTRL registers */
> > +#define OTFPPU_RSZ_DATA_SOURCE         0x04
> > +
> 
> I find the register definitions pretty distracting here (and elsewhere
> in the driver), I suppose my personal preference would be to hide them
> in the headers.

I do not have a strong preference on this.  Okay, will do that to make
it easier for you to look at the driver :)

> > +#define GL_NUM                         2
> > +#define VL_NUM                         3
> > +
> > +enum vou_chn_type {
> > +       VOU_CHN_MAIN,
> > +       VOU_CHN_AUX,
> > +};
> > +
> > +struct zx_crtc_regs {
> > +       u32 fir_active;
> > +       u32 fir_htiming;
> > +       u32 fir_vtiming;
> > +       u32 timing_shift;
> > +       u32 timing_pi_shift;
> > +};

<snip>

> > +static inline struct drm_crtc *zx_find_crtc(struct drm_device *drm, int pipe)
> > +{
> > +       struct drm_crtc *crtc;
> > +       int i = 0;
> > +
> > +       list_for_each_entry(crtc, &drm->mode_config.crtc_list, head)
> > +               if (i++ == pipe)
> > +                       return crtc;
> > +
> > +       return NULL;
> > +}
> 
> We have drm_plane_from_index, it seems like at least 2 drivers would
> benefit from drm_crtc_from_index. Either way, you should probably
> change this code to compare pipe to crtc->index instead of rolling
> your own index counter.

Right.  I will change it to use crtc->index at this point.  And after
the driver gets landed, I will cook up a patch for drm_crtc_from_index.

> > +int zx_vou_enable_vblank(struct drm_device *drm, unsigned int pipe)
> > +{
> > +       struct drm_crtc *crtc;
> > +       struct zx_vou_hw *vou;
> > +
> > +       crtc = zx_find_crtc(drm, pipe);
> > +       if (!crtc)
> > +               return 0;
> > +
> > +       vou = crtc_to_vou(crtc);
> > +
> > +       if (pipe == 0)
> > +               zx_writel_mask(vou->timing + TIMING_INT_CTRL,
> > +                              TIMING_INT_MAIN_FRAME, TIMING_INT_MAIN_FRAME);
> > +       else
> > +               zx_writel_mask(vou->timing + TIMING_INT_CTRL,
> > +                              TIMING_INT_AUX_FRAME, TIMING_INT_AUX_FRAME);
> > +
> 
> It seems like this could also benefit from crtc_bits/crtc_regs

Yes, you're right.

Thanks for all the comments.

Shawn

> > +       return 0;
> > +}

^ permalink raw reply

* [PATCH] fpga zynq: Check the bitstream for validity
From: Jason Gunthorpe @ 2016-10-27 14:39 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <c0e99b6e-ae72-5c64-34c1-91865d0e00b5@suse.com>

On Thu, Oct 27, 2016 at 10:50:48AM +0200, Matthias Brugger wrote:
> >+		/* Sanity check the proposed bitstream. It must start with the
> >+		 * sync word in the correct byte order and be a multiple of 4
> >+		 * bytes.
> >+		 */
> >+		if (count <= 4 || buf[0] != 0x66 || buf[1] != 0x55 ||
> >+		    buf[2] != 0x99 || buf[3] != 0xaa) {
>
> This checks if the bit stream is bigger then 4 bytes. We error out before,
> if it is smaller.

We do? Where?

> So you should fix the wording in the comment and check for count ==
> 4.

Ah right, the comment reflected an earlier revision that had the
length check here.

The count <= 4 should stay here since it is primarily guarding against
read past the buffer in the if.

Jason

^ permalink raw reply

* [PATCH] drm/sun4i: Add a few formats
From: Maxime Ripard @ 2016-10-27 14:35 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <CAGb2v65=6YGaaC3QimPHyP=FKJofygReozmnKLV8CGXvjWGtvQ@mail.gmail.com>

Hi,

On Tue, Oct 25, 2016 at 08:42:26AM +0800, Chen-Yu Tsai wrote:
> On Mon, Oct 24, 2016 at 10:40 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > Hi,
> >
> > On Fri, Oct 21, 2016 at 11:15:32AM +0800, Chen-Yu Tsai wrote:
> >> On Tue, Oct 18, 2016 at 4:46 PM, Maxime Ripard
> >> <maxime.ripard@free-electrons.com> wrote:
> >> > The planes can do more than what was previously exposed. Add support for
> >> > them.
> >> >
> >> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> >> > ---
> >> >  drivers/gpu/drm/sun4i/sun4i_backend.c | 20 ++++++++++++++++++++
> >> >  drivers/gpu/drm/sun4i/sun4i_layer.c   |  6 ++++++
> >> >  2 files changed, 26 insertions(+)
> >> >
> >> > diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
> >> > index afb7ddf660ef..b184a476a480 100644
> >> > --- a/drivers/gpu/drm/sun4i/sun4i_backend.c
> >> > +++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
> >> > @@ -96,6 +96,22 @@ static int sun4i_backend_drm_format_to_layer(struct drm_plane *plane,
> >> >                 *mode = SUN4I_BACKEND_LAY_FBFMT_ARGB8888;
> >> >                 break;
> >> >
> >> > +       case DRM_FORMAT_ARGB4444:
> >> > +               *mode = SUN4I_BACKEND_LAY_FBFMT_ARGB4444;
> >> > +               break;
> >> > +
> >> > +       case DRM_FORMAT_ARGB1555:
> >> > +               *mode = SUN4I_BACKEND_LAY_FBFMT_ARGB1555;
> >> > +               break;
> >> > +
> >> > +       case DRM_FORMAT_RGBA5551:
> >> > +               *mode = SUN4I_BACKEND_LAY_FBFMT_RGBA5551;
> >> > +               break;
> >> > +
> >> > +       case DRM_FORMAT_RGBA4444:
> >> > +               *mode = SUN4I_BACKEND_LAY_FBFMT_RGBA4444;
> >>
> >> The A20 manual only lists ARGB4444, not RGBA4444. There might be
> >> some discrepancy here. We can deal with them
> >
> > Hmm, yes, that's weird. But I guess this would be part of porting it
> > to the A20.
> >
> >> Also there are some more formats missing from the list, could you
> >> add them as well?
> >
> > Which one do you refer to?
> 
> RGB556 and RGB655.

These formats are not supported by Linux yet though.

Thanks,
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 801 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20161027/0673d783/attachment.sig>

^ permalink raw reply

* [PATCH v3] ARM: davinci: da8xx: Fix some redefined symbol warnings
From: Alexandre Bailon @ 2016-10-27 14:33 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <ca32fd12-5299-02e8-24c4-501dda4291ab@ti.com>

On 10/27/2016 01:54 PM, Sekhar Nori wrote:
> On Thursday 27 October 2016 05:13 PM, Sekhar Nori wrote:
>> On Wednesday 26 October 2016 06:09 PM, Alexandre Bailon wrote:
>>> Some macro for DA8xx CFGCHIP are defined in usb-davinci.h,
>>> but da8xx-cfgchip.h intend to replace them.
>>> The usb-da8xx.c is using both headers, causing redefined symbol warnings.
>>
>> Looks like this is not true for v4.9-rc2 and so I don't see any warnings
> 
> Ah, just noticed that _this_ is the patch that introduces
> da8xx-cfgchip.h into usb-da8xx.c. So this is the patch that introduces
> the warnings (and fixes them).
> 
> I can queue this for v4.10 (with Greg's ack) if you change the
> description to make it about cleaning up duplicated defines between
> da8xx-cfgchip.h and usb-davinci.h and not talk about "redefined symbol
> warnings".
I will do it.
> 
> Also, when adding a header file, can you please keep it sorted in
> alphabetical order.
Ok.
> 
> Thanks,
> Sekhar
> 
Thanks,
Alexandre

^ permalink raw reply

* [PATCH] fpga zynq: Check the bitstream for validity
From: Jason Gunthorpe @ 2016-10-27 14:32 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <bdae79f1-dfed-d735-cb49-9ce8aa0b6e4f@xilinx.com>

On Thu, Oct 27, 2016 at 09:42:03AM +0200, Michal Simek wrote:

> I am not quite sure about this and I didn't try it on real hw.
> But minimum bitstream size 52+B and more likely much more than this.

Oh probably, I didn't try to guess what the minimum size is, that
check is just to prevent reading past the end of the buffer.

> This is taken from u-boot source code and this is full BIN header.
> The code above is checking only the last word.

There can be garbage before the sync word.  The hardware ignores
everything till it gets the sync word.  Prior versions of the driver
with the autodetection would discard the garbage.

Since the autodetection was ripped out I didn't want to search since
the intent seems to be for user space to provide a full bitstream,
which should start at the sync word, but that is another option.

>        0x000000bb, /* Sync word */
>        0x11220044, /* Sync word */
>        DUMMY_WORD,
>        DUMMY_WORD,
>        0xaa995566, /* Sync word */

This is the bus width detection pattern, I understood the Zync DevC
interface was wired to 32 bits and did not respond to this.

Jason

^ permalink raw reply

* [RFC PATCH 0/5] Add an overlay manager to handle board capes
From: Antoine Tenart @ 2016-10-27 14:25 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <CAL_JsqL9yWBj0yYE54XGi87YPGugGAACzr=CuW6dk5kk3EuyCA@mail.gmail.com>

Hi Rob,

On Thu, Oct 27, 2016 at 08:41:56AM -0500, Rob Herring wrote:
> Please Cc the maintainers of drivers/of/.
> 
> + Frank R, Hans, Dmitry S

Yes, sorry for that.

> On Wed, Oct 26, 2016 at 9:57 AM, Antoine Tenart
> <antoine.tenart@free-electrons.com> wrote:
> >
> > Many boards now come with dips and compatible capes; among others the
> > C.H.I.P, or Beaglebones. All these boards have a kernel implementing an
> > out-of-tree "cape manager" which is used to detected capes, retrieve
> > their description and apply a corresponding overlay. This series is an
> > attempt to start a discussion, with an implementation of such a manager
> > which is somehow generic (i.e. formats or cape detectors can be added).
> > Other use cases could make use of this manager to dynamically load dt
> > overlays based on some input / hw presence.
> 
> I'd like to see an input source be the kernel command line and/or a DT
> chosen property.

We now have overlay support in U-Boot so we could modify the device tree
from the bootloader and not use the command line. But you can argue the
boot loader can't always be upgraded (to support overlays, or to improve
it). So I guess we can think of using the command line as a input
source.

> Another overlay manager was proposed not to long ago[1] as well.

Thanks for the hint.

> Another thing to consider is different sources of overlays. Besides in
> the filesystem, overlays could be built into the kernel (already
> supported), embedded in the dtb (as the other overlay mgr did) or we
> could extend FDT format to append them.

Sure. Using this series it should be quite easy to support other
sources. We would need to improve the function loading the overlay, to
try other sources. This could even comes in following up patches.

> > The proposed design is a library which can be used by detector drivers
> > to parse headers and load the corresponding overlay. Helpers are
> > provided for this purpose. The whole thing is divided into 3 entities:
> >
> > - The parser which is project-specific (to allow supporting headers
> >   already into the wild). It registers a function parsing an header's
> >   data and filling one or more strings which will be used to find
> >   matching dtbo on the fs.
> >
> > - The overlay manager helpers allowing to parse a header to retrieve
> >   the previously mentioned strings and to load a compatible overlay.
> >
> > - The detectors which are used to detect capes and get their description
> >   (to be parsed).
> 
> What about things like power has to be turned on first to detect
> boards and read their ID? I think this needs to be tied into the
> driver model. Though, don't go sticking cape mgr nodes into DT. Maybe
> a driver gets bound to a connector node, but we've got to sort out
> connector bindings first.

Right. I don't know yet how to handle this. Do you have an existing
example in mind of such a power requirement?

> > An example of parser and detector is given, compatible with what's done
> > for the C.H.I.P. As the w1 framework is really bad (and we should
> > probably do something about that) the detector code is far from being
> > perfect; but that's not related to what we try to achieve here.
> >
> > The actual implementation has a limitation: the detectors cannot be
> > built-in the kernel image as they would likely detect capes at boot time
> > but will fail to get their corresponding dt overlays as the fs isn't
> > mounted yet. The only case this can work is when dt overlays are
> > built-in firmwares. This isn't an issue for the C.H.I.P. use case right
> > now. There was a discussion about making an helper to wait for the
> > rootfs to be mount but the answer was "this is the driver's problem".
> 
> I thought there are firmware loading calls that will wait. I think
> this all needs to work asynchronously both for firmware loading and
> because w1 is really slow.

There is an asynchronous one, but it will also fail if the rootfs isn't
mounted yet.

Thanks!

Antoine

-- 
Antoine T?nart, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 801 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20161027/30ab5fd8/attachment-0001.sig>

^ permalink raw reply


This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox