* [PATCH v2 0/2] amba/platform: Initialize dma_parms at the bus level
@ 2020-03-31 18:38 ` Ulf Hansson
0 siblings, 0 replies; 15+ messages in thread
From: Ulf Hansson @ 2020-03-31 18:38 UTC (permalink / raw)
To: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel
Cc: Ulf Hansson, Arnd Bergmann, Linus Walleij, Russell King,
Haibo Chen, Vinod Koul, linux-arm-kernel, dmaengine, Robin Murphy,
Christoph Hellwig, Ludovic Barre
It's currently the amba/platform driver's responsibility to initialize the
pointer, dma_parms, for its corresponding struct device. The benefit with this
approach allows us to avoid the initialization and to not waste memory for the
struct device_dma_parameters, as this can be decided on a case by case basis.
However, it has turned out that this approach is not very practical. Not only
does it lead to open coding, but also to real errors. In principle callers of
dma_set_max_seg_size() doesn't check the error code, but just assumes it
succeeds.
For these reasons, this series initializes the dma_parms from the amba/platform
bus at the device registration point. This also follows the way the PCI devices
are being managed, see pci_device_add().
If it turns out that this is an acceptable solution, we probably also want the
changes for stable, but I am not sure if it applies without conflicts.
The series is based on v5.6.
Kind regards
Ulf Hansson
Ulf Hansson (2):
driver core: platform: Initialize dma_parms for platform devices
amba: Initialize dma_parms for amba devices
drivers/amba/bus.c | 1 +
drivers/base/platform.c | 2 ++
include/linux/amba/bus.h | 1 +
include/linux/platform_device.h | 1 +
4 files changed, 5 insertions(+)
--
2.20.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 15+ messages in thread* [PATCH v2 1/2] driver core: platform: Initialize dma_parms for platform devices
2020-03-31 18:38 ` Ulf Hansson
@ 2020-03-31 18:38 ` Ulf Hansson
-1 siblings, 0 replies; 15+ messages in thread
From: Ulf Hansson @ 2020-03-31 18:38 UTC (permalink / raw)
To: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel
Cc: Arnd Bergmann, Christoph Hellwig, Russell King, Linus Walleij,
Robin Murphy, Vinod Koul, Haibo Chen, Ludovic Barre,
linux-arm-kernel, dmaengine, Ulf Hansson, stable
It's currently the platform driver's responsibility to initialize the
pointer, dma_parms, for its corresponding struct device. The benefit with
this approach allows us to avoid the initialization and to not waste memory
for the struct device_dma_parameters, as this can be decided on a case by
case basis.
However, it has turned out that this approach is not very practical. Not
only does it lead to open coding, but also to real errors. In principle
callers of dma_set_max_seg_size() doesn't check the error code, but just
assumes it succeeds.
For these reasons, let's do the initialization from the common platform bus
at the device registration point. This also follows the way the PCI devices
are being managed, see pci_device_add().
Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
Changes in v2:
- Move initialization to setup_pdev_dma_masks(). This means the
initialization is done also in the OF path.
---
drivers/base/platform.c | 2 ++
include/linux/platform_device.h | 1 +
2 files changed, 3 insertions(+)
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index b5ce7b085795..c81b68d5d66d 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -361,6 +361,8 @@ struct platform_object {
*/
static void setup_pdev_dma_masks(struct platform_device *pdev)
{
+ pdev->dev.dma_parms = &pdev->dma_parms;
+
if (!pdev->dev.coherent_dma_mask)
pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
if (!pdev->dev.dma_mask) {
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 041bfa412aa0..81900b3cbe37 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -25,6 +25,7 @@ struct platform_device {
bool id_auto;
struct device dev;
u64 platform_dma_mask;
+ struct device_dma_parameters dma_parms;
u32 num_resources;
struct resource *resource;
--
2.20.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 1/2] driver core: platform: Initialize dma_parms for platform devices
@ 2020-03-31 18:38 ` Ulf Hansson
0 siblings, 0 replies; 15+ messages in thread
From: Ulf Hansson @ 2020-03-31 18:38 UTC (permalink / raw)
To: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel
Cc: Ulf Hansson, Arnd Bergmann, Linus Walleij, Russell King,
Haibo Chen, Vinod Koul, linux-arm-kernel, dmaengine, stable,
Robin Murphy, Christoph Hellwig, Ludovic Barre
It's currently the platform driver's responsibility to initialize the
pointer, dma_parms, for its corresponding struct device. The benefit with
this approach allows us to avoid the initialization and to not waste memory
for the struct device_dma_parameters, as this can be decided on a case by
case basis.
However, it has turned out that this approach is not very practical. Not
only does it lead to open coding, but also to real errors. In principle
callers of dma_set_max_seg_size() doesn't check the error code, but just
assumes it succeeds.
For these reasons, let's do the initialization from the common platform bus
at the device registration point. This also follows the way the PCI devices
are being managed, see pci_device_add().
Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
Changes in v2:
- Move initialization to setup_pdev_dma_masks(). This means the
initialization is done also in the OF path.
---
drivers/base/platform.c | 2 ++
include/linux/platform_device.h | 1 +
2 files changed, 3 insertions(+)
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index b5ce7b085795..c81b68d5d66d 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -361,6 +361,8 @@ struct platform_object {
*/
static void setup_pdev_dma_masks(struct platform_device *pdev)
{
+ pdev->dev.dma_parms = &pdev->dma_parms;
+
if (!pdev->dev.coherent_dma_mask)
pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
if (!pdev->dev.dma_mask) {
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 041bfa412aa0..81900b3cbe37 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -25,6 +25,7 @@ struct platform_device {
bool id_auto;
struct device dev;
u64 platform_dma_mask;
+ struct device_dma_parameters dma_parms;
u32 num_resources;
struct resource *resource;
--
2.20.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 15+ messages in thread* RE: [PATCH v2 1/2] driver core: platform: Initialize dma_parms for platform devices
2020-03-31 18:38 ` Ulf Hansson
@ 2020-04-01 4:06 ` BOUGH CHEN
-1 siblings, 0 replies; 15+ messages in thread
From: BOUGH CHEN @ 2020-04-01 4:06 UTC (permalink / raw)
To: Ulf Hansson, Greg Kroah-Hartman, Rafael J . Wysocki,
linux-kernel@vger.kernel.org
Cc: Arnd Bergmann, Christoph Hellwig, Russell King, Linus Walleij,
Robin Murphy, Vinod Koul, Ludovic Barre,
linux-arm-kernel@lists.infradead.org, dmaengine@vger.kernel.org,
stable@vger.kernel.org
> -----Original Message-----
> From: Ulf Hansson <ulf.hansson@linaro.org>
> Sent: 2020年4月1日 2:39
> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Rafael J . Wysocki
> <rafael@kernel.org>; linux-kernel@vger.kernel.org
> Cc: Arnd Bergmann <arnd@arndb.de>; Christoph Hellwig <hch@lst.de>;
> Russell King <linux@armlinux.org.uk>; Linus Walleij
> <linus.walleij@linaro.org>; Robin Murphy <robin.murphy@arm.com>; Vinod
> Koul <vkoul@kernel.org>; BOUGH CHEN <haibo.chen@nxp.com>; Ludovic
> Barre <ludovic.barre@st.com>; linux-arm-kernel@lists.infradead.org;
> dmaengine@vger.kernel.org; Ulf Hansson <ulf.hansson@linaro.org>;
> stable@vger.kernel.org
> Subject: [PATCH v2 1/2] driver core: platform: Initialize dma_parms for
> platform devices
>
> It's currently the platform driver's responsibility to initialize the pointer,
> dma_parms, for its corresponding struct device. The benefit with this
> approach allows us to avoid the initialization and to not waste memory for
> the struct device_dma_parameters, as this can be decided on a case by case
> basis.
>
> However, it has turned out that this approach is not very practical. Not
> only does it lead to open coding, but also to real errors. In principle callers of
> dma_set_max_seg_size() doesn't check the error code, but just assumes it
> succeeds.
>
> For these reasons, let's do the initialization from the common platform bus
> at the device registration point. This also follows the way the PCI devices are
> being managed, see pci_device_add().
>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
>
Hi Ulf,
I test both on our local 5.4.24 branch and the latest Linux-next, both works fine.
Tested-by: Haibo Chen <haibo.chen@nxp.com>
Best Regards
Haibo Chen
> ---
>
> Changes in v2:
> - Move initialization to setup_pdev_dma_masks(). This means the
> initialization is done also in the OF path.
>
> ---
> drivers/base/platform.c | 2 ++
> include/linux/platform_device.h | 1 +
> 2 files changed, 3 insertions(+)
>
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c index
> b5ce7b085795..c81b68d5d66d 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -361,6 +361,8 @@ struct platform_object {
> */
> static void setup_pdev_dma_masks(struct platform_device *pdev) {
> + pdev->dev.dma_parms = &pdev->dma_parms;
> +
> if (!pdev->dev.coherent_dma_mask)
> pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
> if (!pdev->dev.dma_mask) {
> diff --git a/include/linux/platform_device.h
> b/include/linux/platform_device.h index 041bfa412aa0..81900b3cbe37
> 100644
> --- a/include/linux/platform_device.h
> +++ b/include/linux/platform_device.h
> @@ -25,6 +25,7 @@ struct platform_device {
> bool id_auto;
> struct device dev;
> u64 platform_dma_mask;
> + struct device_dma_parameters dma_parms;
> u32 num_resources;
> struct resource *resource;
>
> --
> 2.20.1
^ permalink raw reply [flat|nested] 15+ messages in thread* RE: [PATCH v2 1/2] driver core: platform: Initialize dma_parms for platform devices
@ 2020-04-01 4:06 ` BOUGH CHEN
0 siblings, 0 replies; 15+ messages in thread
From: BOUGH CHEN @ 2020-04-01 4:06 UTC (permalink / raw)
To: Ulf Hansson, Greg Kroah-Hartman, Rafael J . Wysocki,
linux-kernel@vger.kernel.org
Cc: Arnd Bergmann, Linus Walleij, Russell King,
stable@vger.kernel.org, Vinod Koul,
linux-arm-kernel@lists.infradead.org, dmaengine@vger.kernel.org,
Robin Murphy, Christoph Hellwig, Ludovic Barre
> -----Original Message-----
> From: Ulf Hansson <ulf.hansson@linaro.org>
> Sent: 2020年4月1日 2:39
> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Rafael J . Wysocki
> <rafael@kernel.org>; linux-kernel@vger.kernel.org
> Cc: Arnd Bergmann <arnd@arndb.de>; Christoph Hellwig <hch@lst.de>;
> Russell King <linux@armlinux.org.uk>; Linus Walleij
> <linus.walleij@linaro.org>; Robin Murphy <robin.murphy@arm.com>; Vinod
> Koul <vkoul@kernel.org>; BOUGH CHEN <haibo.chen@nxp.com>; Ludovic
> Barre <ludovic.barre@st.com>; linux-arm-kernel@lists.infradead.org;
> dmaengine@vger.kernel.org; Ulf Hansson <ulf.hansson@linaro.org>;
> stable@vger.kernel.org
> Subject: [PATCH v2 1/2] driver core: platform: Initialize dma_parms for
> platform devices
>
> It's currently the platform driver's responsibility to initialize the pointer,
> dma_parms, for its corresponding struct device. The benefit with this
> approach allows us to avoid the initialization and to not waste memory for
> the struct device_dma_parameters, as this can be decided on a case by case
> basis.
>
> However, it has turned out that this approach is not very practical. Not
> only does it lead to open coding, but also to real errors. In principle callers of
> dma_set_max_seg_size() doesn't check the error code, but just assumes it
> succeeds.
>
> For these reasons, let's do the initialization from the common platform bus
> at the device registration point. This also follows the way the PCI devices are
> being managed, see pci_device_add().
>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
>
Hi Ulf,
I test both on our local 5.4.24 branch and the latest Linux-next, both works fine.
Tested-by: Haibo Chen <haibo.chen@nxp.com>
Best Regards
Haibo Chen
> ---
>
> Changes in v2:
> - Move initialization to setup_pdev_dma_masks(). This means the
> initialization is done also in the OF path.
>
> ---
> drivers/base/platform.c | 2 ++
> include/linux/platform_device.h | 1 +
> 2 files changed, 3 insertions(+)
>
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c index
> b5ce7b085795..c81b68d5d66d 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -361,6 +361,8 @@ struct platform_object {
> */
> static void setup_pdev_dma_masks(struct platform_device *pdev) {
> + pdev->dev.dma_parms = &pdev->dma_parms;
> +
> if (!pdev->dev.coherent_dma_mask)
> pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
> if (!pdev->dev.dma_mask) {
> diff --git a/include/linux/platform_device.h
> b/include/linux/platform_device.h index 041bfa412aa0..81900b3cbe37
> 100644
> --- a/include/linux/platform_device.h
> +++ b/include/linux/platform_device.h
> @@ -25,6 +25,7 @@ struct platform_device {
> bool id_auto;
> struct device dev;
> u64 platform_dma_mask;
> + struct device_dma_parameters dma_parms;
> u32 num_resources;
> struct resource *resource;
>
> --
> 2.20.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v2 1/2] driver core: platform: Initialize dma_parms for platform devices
2020-03-31 18:38 ` Ulf Hansson
(?)
(?)
@ 2020-04-01 14:52 ` Sasha Levin
-1 siblings, 0 replies; 15+ messages in thread
From: Sasha Levin @ 2020-04-01 14:52 UTC (permalink / raw)
To: Sasha Levin, Ulf Hansson, Greg Kroah-Hartman
Cc: Arnd Bergmann, Christoph Hellwig, stable, stable
Hi
[This is an automated email]
This commit has been processed because it contains a -stable tag.
The stable tag indicates that it's relevant for the following trees: all
The bot has tested the following trees: v5.5.13, v5.4.28, v4.19.113, v4.14.174, v4.9.217, v4.4.217.
v5.5.13: Build OK!
v5.4.28: Build OK!
v4.19.113: Failed to apply! Possible dependencies:
cdfee5623290 ("driver core: initialize a default DMA mask for platform device")
e3a36eb6dfae ("driver code: clarify and fix platform device DMA mask allocation")
v4.14.174: Failed to apply! Possible dependencies:
186c446f4b84 ("media: arch: sh: migor: Use new renesas-ceu camera driver")
1a3c230b4151 ("media: arch: sh: ms7724se: Use new renesas-ceu camera driver")
39fb993038e1 ("media: arch: sh: ap325rxa: Use new renesas-ceu camera driver")
b12c8a70643f ("m68k: Set default dma mask for platform devices")
c2f9b05fd5c1 ("media: arch: sh: ecovec: Use new renesas-ceu camera driver")
cdfee5623290 ("driver core: initialize a default DMA mask for platform device")
e3a36eb6dfae ("driver code: clarify and fix platform device DMA mask allocation")
f3590dc32974 ("media: arch: sh: kfr2r09: Use new renesas-ceu camera driver")
v4.9.217: Failed to apply! Possible dependencies:
186c446f4b84 ("media: arch: sh: migor: Use new renesas-ceu camera driver")
1a3c230b4151 ("media: arch: sh: ms7724se: Use new renesas-ceu camera driver")
39fb993038e1 ("media: arch: sh: ap325rxa: Use new renesas-ceu camera driver")
8fd708157a59 ("Input: tsc2007 - move header file out of I2C realm")
b12c8a70643f ("m68k: Set default dma mask for platform devices")
c2f9b05fd5c1 ("media: arch: sh: ecovec: Use new renesas-ceu camera driver")
cdfee5623290 ("driver core: initialize a default DMA mask for platform device")
e3a36eb6dfae ("driver code: clarify and fix platform device DMA mask allocation")
f14434040ce0 ("Input: tsc2007 - add iio interface to read external ADC input and temperature")
f3590dc32974 ("media: arch: sh: kfr2r09: Use new renesas-ceu camera driver")
v4.4.217: Failed to apply! Possible dependencies:
166dd7d3fbf2 ("powerpc/64: Move MMU backend selection out of platform code")
340f3039acd6 ("m68k: convert to dma_map_ops")
3808a88985b4 ("powerpc: Move FW feature probing out of pseries probe()")
406b0b6ae3fc ("powerpc/64: Move 64-bit probe_machine() to later in the boot process")
565713840445 ("powerpc: Move 32-bit probe() machine to later in the boot process")
5d31a96e6c01 ("powerpc/livepatch: Add livepatch stack to struct thread_info")
63c254a50104 ("powerpc: Add comment explaining the purpose of setup_kdump_trampoline()")
b12c8a70643f ("m68k: Set default dma mask for platform devices")
b1923caa6e64 ("powerpc: Merge 32-bit and 64-bit setup_arch()")
cdfee5623290 ("driver core: initialize a default DMA mask for platform device")
da6a97bf12d5 ("powerpc: Move epapr_paravirt_early_init() to early_init_devtree()")
f63e6d898760 ("powerpc/livepatch: Add livepatch header")
NOTE: The patch will not be queued to stable trees until it is upstream.
How should we proceed with this patch?
--
Thanks
Sasha
^ permalink raw reply [flat|nested] 15+ messages in thread* Re: [PATCH v2 1/2] driver core: platform: Initialize dma_parms for platform devices
2020-03-31 18:38 ` Ulf Hansson
@ 2020-04-22 9:41 ` Arnd Bergmann
-1 siblings, 0 replies; 15+ messages in thread
From: Arnd Bergmann @ 2020-04-22 9:41 UTC (permalink / raw)
To: Ulf Hansson
Cc: Greg Kroah-Hartman, Rafael J . Wysocki,
linux-kernel@vger.kernel.org, Christoph Hellwig, Russell King,
Linus Walleij, Robin Murphy, Vinod Koul, Haibo Chen,
Ludovic Barre, Linux ARM, dmaengine, # 3.4.x
On Tue, Mar 31, 2020 at 8:38 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> It's currently the platform driver's responsibility to initialize the
> pointer, dma_parms, for its corresponding struct device. The benefit with
> this approach allows us to avoid the initialization and to not waste memory
> for the struct device_dma_parameters, as this can be decided on a case by
> case basis.
>
> However, it has turned out that this approach is not very practical. Not
> only does it lead to open coding, but also to real errors. In principle
> callers of dma_set_max_seg_size() doesn't check the error code, but just
> assumes it succeeds.
>
> For these reasons, let's do the initialization from the common platform bus
> at the device registration point. This also follows the way the PCI devices
> are being managed, see pci_device_add().
>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v2 1/2] driver core: platform: Initialize dma_parms for platform devices
@ 2020-04-22 9:41 ` Arnd Bergmann
0 siblings, 0 replies; 15+ messages in thread
From: Arnd Bergmann @ 2020-04-22 9:41 UTC (permalink / raw)
To: Ulf Hansson
Cc: Rafael J . Wysocki, Greg Kroah-Hartman, Linus Walleij,
Russell King, Haibo Chen, linux-kernel@vger.kernel.org,
Vinod Koul, Linux ARM, dmaengine, # 3.4.x, Robin Murphy,
Christoph Hellwig, Ludovic Barre
On Tue, Mar 31, 2020 at 8:38 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> It's currently the platform driver's responsibility to initialize the
> pointer, dma_parms, for its corresponding struct device. The benefit with
> this approach allows us to avoid the initialization and to not waste memory
> for the struct device_dma_parameters, as this can be decided on a case by
> case basis.
>
> However, it has turned out that this approach is not very practical. Not
> only does it lead to open coding, but also to real errors. In principle
> callers of dma_set_max_seg_size() doesn't check the error code, but just
> assumes it succeeds.
>
> For these reasons, let's do the initialization from the common platform bus
> at the device registration point. This also follows the way the PCI devices
> are being managed, see pci_device_add().
>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 15+ messages in thread
* [PATCH v2 2/2] amba: Initialize dma_parms for amba devices
2020-03-31 18:38 ` Ulf Hansson
@ 2020-03-31 18:38 ` Ulf Hansson
-1 siblings, 0 replies; 15+ messages in thread
From: Ulf Hansson @ 2020-03-31 18:38 UTC (permalink / raw)
To: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel
Cc: Arnd Bergmann, Christoph Hellwig, Russell King, Linus Walleij,
Robin Murphy, Vinod Koul, Haibo Chen, Ludovic Barre,
linux-arm-kernel, dmaengine, Ulf Hansson, stable
It's currently the amba driver's responsibility to initialize the pointer,
dma_parms, for its corresponding struct device. The benefit with this
approach allows us to avoid the initialization and to not waste memory for
the struct device_dma_parameters, as this can be decided on a case by case
basis.
However, it has turned out that this approach is not very practical. Not
only does it lead to open coding, but also to real errors. In principle
callers of dma_set_max_seg_size() doesn't check the error code, but just
assumes it succeeds.
For these reasons, let's do the initialization from the common amba bus at
the device registration point. This also follows the way the PCI devices
are being managed, see pci_device_add().
Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
Changes in v2:
- Move initialization to amba_device_initialize() to be more consistent
with how we manage platform devices.
---
drivers/amba/bus.c | 1 +
include/linux/amba/bus.h | 1 +
2 files changed, 2 insertions(+)
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index fe1523664816..8558b629880b 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -645,6 +645,7 @@ static void amba_device_initialize(struct amba_device *dev, const char *name)
dev->dev.release = amba_device_release;
dev->dev.bus = &amba_bustype;
dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
+ dev->dev.dma_parms = &dev->dma_parms;
dev->res.name = dev_name(&dev->dev);
}
diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h
index 26f0ecf401ea..0bbfd647f5c6 100644
--- a/include/linux/amba/bus.h
+++ b/include/linux/amba/bus.h
@@ -65,6 +65,7 @@ struct amba_device {
struct device dev;
struct resource res;
struct clk *pclk;
+ struct device_dma_parameters dma_parms;
unsigned int periphid;
unsigned int cid;
struct amba_cs_uci_id uci;
--
2.20.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v2 2/2] amba: Initialize dma_parms for amba devices
@ 2020-03-31 18:38 ` Ulf Hansson
0 siblings, 0 replies; 15+ messages in thread
From: Ulf Hansson @ 2020-03-31 18:38 UTC (permalink / raw)
To: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel
Cc: Ulf Hansson, Arnd Bergmann, Linus Walleij, Russell King,
Haibo Chen, Vinod Koul, linux-arm-kernel, dmaengine, stable,
Robin Murphy, Christoph Hellwig, Ludovic Barre
It's currently the amba driver's responsibility to initialize the pointer,
dma_parms, for its corresponding struct device. The benefit with this
approach allows us to avoid the initialization and to not waste memory for
the struct device_dma_parameters, as this can be decided on a case by case
basis.
However, it has turned out that this approach is not very practical. Not
only does it lead to open coding, but also to real errors. In principle
callers of dma_set_max_seg_size() doesn't check the error code, but just
assumes it succeeds.
For these reasons, let's do the initialization from the common amba bus at
the device registration point. This also follows the way the PCI devices
are being managed, see pci_device_add().
Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
Changes in v2:
- Move initialization to amba_device_initialize() to be more consistent
with how we manage platform devices.
---
drivers/amba/bus.c | 1 +
include/linux/amba/bus.h | 1 +
2 files changed, 2 insertions(+)
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index fe1523664816..8558b629880b 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -645,6 +645,7 @@ static void amba_device_initialize(struct amba_device *dev, const char *name)
dev->dev.release = amba_device_release;
dev->dev.bus = &amba_bustype;
dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
+ dev->dev.dma_parms = &dev->dma_parms;
dev->res.name = dev_name(&dev->dev);
}
diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h
index 26f0ecf401ea..0bbfd647f5c6 100644
--- a/include/linux/amba/bus.h
+++ b/include/linux/amba/bus.h
@@ -65,6 +65,7 @@ struct amba_device {
struct device dev;
struct resource res;
struct clk *pclk;
+ struct device_dma_parameters dma_parms;
unsigned int periphid;
unsigned int cid;
struct amba_cs_uci_id uci;
--
2.20.1
_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 15+ messages in thread* Re: [PATCH v2 2/2] amba: Initialize dma_parms for amba devices
2020-03-31 18:38 ` Ulf Hansson
@ 2020-04-22 9:42 ` Arnd Bergmann
-1 siblings, 0 replies; 15+ messages in thread
From: Arnd Bergmann @ 2020-04-22 9:42 UTC (permalink / raw)
To: Ulf Hansson
Cc: Greg Kroah-Hartman, Rafael J . Wysocki,
linux-kernel@vger.kernel.org, Christoph Hellwig, Russell King,
Linus Walleij, Robin Murphy, Vinod Koul, Haibo Chen,
Ludovic Barre, Linux ARM, dmaengine, # 3.4.x
On Tue, Mar 31, 2020 at 8:38 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> It's currently the amba driver's responsibility to initialize the pointer,
> dma_parms, for its corresponding struct device. The benefit with this
> approach allows us to avoid the initialization and to not waste memory for
> the struct device_dma_parameters, as this can be decided on a case by case
> basis.
>
> However, it has turned out that this approach is not very practical. Not
> only does it lead to open coding, but also to real errors. In principle
> callers of dma_set_max_seg_size() doesn't check the error code, but just
> assumes it succeeds.
>
> For these reasons, let's do the initialization from the common amba bus at
> the device registration point. This also follows the way the PCI devices
> are being managed, see pci_device_add().
>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v2 2/2] amba: Initialize dma_parms for amba devices
@ 2020-04-22 9:42 ` Arnd Bergmann
0 siblings, 0 replies; 15+ messages in thread
From: Arnd Bergmann @ 2020-04-22 9:42 UTC (permalink / raw)
To: Ulf Hansson
Cc: Rafael J . Wysocki, Greg Kroah-Hartman, Linus Walleij,
Russell King, Haibo Chen, linux-kernel@vger.kernel.org,
Vinod Koul, Linux ARM, dmaengine, # 3.4.x, Robin Murphy,
Christoph Hellwig, Ludovic Barre
On Tue, Mar 31, 2020 at 8:38 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> It's currently the amba driver's responsibility to initialize the pointer,
> dma_parms, for its corresponding struct device. The benefit with this
> approach allows us to avoid the initialization and to not waste memory for
> the struct device_dma_parameters, as this can be decided on a case by case
> basis.
>
> However, it has turned out that this approach is not very practical. Not
> only does it lead to open coding, but also to real errors. In principle
> callers of dma_set_max_seg_size() doesn't check the error code, but just
> assumes it succeeds.
>
> For these reasons, let's do the initialization from the common amba bus at
> the device registration point. This also follows the way the PCI devices
> are being managed, see pci_device_add().
>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v2 0/2] amba/platform: Initialize dma_parms at the bus level
2020-03-31 18:38 ` Ulf Hansson
@ 2020-04-17 11:51 ` Ulf Hansson
-1 siblings, 0 replies; 15+ messages in thread
From: Ulf Hansson @ 2020-04-17 11:51 UTC (permalink / raw)
To: Greg Kroah-Hartman, Arnd Bergmann, Linus Walleij
Cc: Christoph Hellwig, Linux Kernel Mailing List, Rafael J . Wysocki,
Russell King, Robin Murphy, Vinod Koul, Haibo Chen, Ludovic Barre,
Linux ARM, dmaengine
- Greg, Arnd, Linus, etc,
On Tue, 31 Mar 2020 at 20:38, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> It's currently the amba/platform driver's responsibility to initialize the
> pointer, dma_parms, for its corresponding struct device. The benefit with this
> approach allows us to avoid the initialization and to not waste memory for the
> struct device_dma_parameters, as this can be decided on a case by case basis.
>
> However, it has turned out that this approach is not very practical. Not only
> does it lead to open coding, but also to real errors. In principle callers of
> dma_set_max_seg_size() doesn't check the error code, but just assumes it
> succeeds.
>
> For these reasons, this series initializes the dma_parms from the amba/platform
> bus at the device registration point. This also follows the way the PCI devices
> are being managed, see pci_device_add().
>
> If it turns out that this is an acceptable solution, we probably also want the
> changes for stable, but I am not sure if it applies without conflicts.
>
> The series is based on v5.6.
>
> Kind regards
> Ulf Hansson
>
>
> Ulf Hansson (2):
> driver core: platform: Initialize dma_parms for platform devices
> amba: Initialize dma_parms for amba devices
>
> drivers/amba/bus.c | 1 +
> drivers/base/platform.c | 2 ++
> include/linux/amba/bus.h | 1 +
> include/linux/platform_device.h | 1 +
> 4 files changed, 5 insertions(+)
>
> --
> 2.20.1
>
Does this look okay or is there anything you would like me to change?
Kind regards
Uffe
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v2 0/2] amba/platform: Initialize dma_parms at the bus level
@ 2020-04-17 11:51 ` Ulf Hansson
0 siblings, 0 replies; 15+ messages in thread
From: Ulf Hansson @ 2020-04-17 11:51 UTC (permalink / raw)
To: Greg Kroah-Hartman, Arnd Bergmann, Linus Walleij
Cc: Rafael J . Wysocki, Russell King, Haibo Chen,
Linux Kernel Mailing List, Vinod Koul, Linux ARM, dmaengine,
Robin Murphy, Christoph Hellwig, Ludovic Barre
- Greg, Arnd, Linus, etc,
On Tue, 31 Mar 2020 at 20:38, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> It's currently the amba/platform driver's responsibility to initialize the
> pointer, dma_parms, for its corresponding struct device. The benefit with this
> approach allows us to avoid the initialization and to not waste memory for the
> struct device_dma_parameters, as this can be decided on a case by case basis.
>
> However, it has turned out that this approach is not very practical. Not only
> does it lead to open coding, but also to real errors. In principle callers of
> dma_set_max_seg_size() doesn't check the error code, but just assumes it
> succeeds.
>
> For these reasons, this series initializes the dma_parms from the amba/platform
> bus at the device registration point. This also follows the way the PCI devices
> are being managed, see pci_device_add().
>
> If it turns out that this is an acceptable solution, we probably also want the
> changes for stable, but I am not sure if it applies without conflicts.
>
> The series is based on v5.6.
>
> Kind regards
> Ulf Hansson
>
>
> Ulf Hansson (2):
> driver core: platform: Initialize dma_parms for platform devices
> amba: Initialize dma_parms for amba devices
>
> drivers/amba/bus.c | 1 +
> drivers/base/platform.c | 2 ++
> include/linux/amba/bus.h | 1 +
> include/linux/platform_device.h | 1 +
> 4 files changed, 5 insertions(+)
>
> --
> 2.20.1
>
Does this look okay or is there anything you would like me to change?
Kind regards
Uffe
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 15+ messages in thread