* Re: [PATCH] fbdev: Use string choices helpers
From: Helge Deller @ 2025-08-24 15:38 UTC (permalink / raw)
To: Chelsy Ratnawat; +Cc: linux-fbdev, dri-devel
In-Reply-To: <20250824152327.2390717-1-chelsyratnawat2001@gmail.com>
On 8/24/25 17:23, Chelsy Ratnawat wrote:
> Use string_choices.h helpers instead of hard-coded strings.
>
> Signed-off-by: Chelsy Ratnawat <chelsyratnawat2001@gmail.com>
> ---
> drivers/video/fbdev/core/fbmon.c | 7 ++++---
> drivers/video/fbdev/nvidia/nvidia.c | 3 ++-
> drivers/video/fbdev/pxafb.c | 3 ++-
> 3 files changed, 8 insertions(+), 5 deletions(-)
applied.
Thanks!
Helge
^ permalink raw reply
* [PATCH] fbdev: Use string choices helpers
From: Chelsy Ratnawat @ 2025-08-24 15:23 UTC (permalink / raw)
To: simona, deller, adaplas
Cc: raag.jadav, linux-fbdev, dri-devel, Chelsy Ratnawat
Use string_choices.h helpers instead of hard-coded strings.
Signed-off-by: Chelsy Ratnawat <chelsyratnawat2001@gmail.com>
---
drivers/video/fbdev/core/fbmon.c | 7 ++++---
drivers/video/fbdev/nvidia/nvidia.c | 3 ++-
drivers/video/fbdev/pxafb.c | 3 ++-
3 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/video/fbdev/core/fbmon.c b/drivers/video/fbdev/core/fbmon.c
index 3b779c27c271..0a65bef01e3c 100644
--- a/drivers/video/fbdev/core/fbmon.c
+++ b/drivers/video/fbdev/core/fbmon.c
@@ -36,6 +36,7 @@
#include <video/of_videomode.h>
#include <video/videomode.h>
#include "../edid.h"
+#include <linux/string_choices.h>
/*
* EDID parser
@@ -320,9 +321,9 @@ static void get_dpms_capabilities(unsigned char flags,
if (flags & DPMS_STANDBY)
specs->dpms |= FB_DPMS_STANDBY;
DPRINTK(" DPMS: Active %s, Suspend %s, Standby %s\n",
- (flags & DPMS_ACTIVE_OFF) ? "yes" : "no",
- (flags & DPMS_SUSPEND) ? "yes" : "no",
- (flags & DPMS_STANDBY) ? "yes" : "no");
+ str_yes_no(flags & DPMS_ACTIVE_OFF),
+ str_yes_no(flags & DPMS_SUSPEND),
+ str_yes_no(flags & DPMS_STANDBY));
}
static void get_chroma(unsigned char *block, struct fb_monspecs *specs)
diff --git a/drivers/video/fbdev/nvidia/nvidia.c b/drivers/video/fbdev/nvidia/nvidia.c
index cfaf9454014d..72b85f475605 100644
--- a/drivers/video/fbdev/nvidia/nvidia.c
+++ b/drivers/video/fbdev/nvidia/nvidia.c
@@ -22,6 +22,7 @@
#include <linux/pci.h>
#include <linux/console.h>
#include <linux/backlight.h>
+#include <linux/string_choices.h>
#ifdef CONFIG_BOOTX_TEXT
#include <asm/btext.h>
#endif
@@ -622,7 +623,7 @@ static int nvidiafb_set_par(struct fb_info *info)
else
par->FPDither = !!(NV_RD32(par->PRAMDAC, 0x083C) & 1);
printk(KERN_INFO PFX "Flat panel dithering %s\n",
- par->FPDither ? "enabled" : "disabled");
+ str_enabled_disabled(par->FPDither));
}
info->fix.visual = (info->var.bits_per_pixel == 8) ?
diff --git a/drivers/video/fbdev/pxafb.c b/drivers/video/fbdev/pxafb.c
index baf87f34cc24..b96a8a96bce8 100644
--- a/drivers/video/fbdev/pxafb.c
+++ b/drivers/video/fbdev/pxafb.c
@@ -60,6 +60,7 @@
#include <linux/soc/pxa/cpu.h>
#include <video/of_display_timing.h>
#include <video/videomode.h>
+#include <linux/string_choices.h>
#include <asm/io.h>
#include <asm/irq.h>
@@ -1419,7 +1420,7 @@ static inline void __pxafb_lcd_power(struct pxafb_info *fbi, int on)
if (ret < 0)
pr_warn("Unable to %s LCD supply regulator: %d\n",
- on ? "enable" : "disable", ret);
+ str_enable_disable(on), ret);
else
fbi->lcd_supply_enabled = on;
}
--
2.47.3
^ permalink raw reply related
* Re: UBSAN: shift-out-of-bounds in drivers/video/fbdev/core/fb_fillrect.h:100:21 (v6.17-rc2)
From: Erhard Furtner @ 2025-08-22 15:55 UTC (permalink / raw)
To: Kajtár Zsolt, linux-fbdev; +Cc: dri-devel
In-Reply-To: <9473ef5b-c298-56b1-0051-e10bb3b4dd67@c64.rulez.org>
> It's only on 32 bit big endian. I don't have UBSAN for MIPS on my setup
> so haven't noticed it.
>
> #ifndef __LITTLE_ENDIAN
> pattern <<= (BITS_PER_LONG % bpp);
> pattern |= pattern >> bpp; <-
> #endif
>
> In the 32 BPP case the result is identical in both the no shift and zero
> result implementations.
>
> I've patched it by skipping this realignment as it's only needed if the
> BPP is smaller than the word length.
Thanks for looking into this!
Applied your patch from
https://lore.kernel.org/linux-fbdev/20250821024248.7458-1-soci@c64.rulez.org/T/#u
which fixes the USBAN hit for me.
Greetings,
Erhard
^ permalink raw reply
* Re: [PATCH v2 1/4] dt-bindings: backlight: Add max25014 bindings
From: Maud Spierings @ 2025-08-22 7:35 UTC (permalink / raw)
To: Daniel Thompson
Cc: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam, dri-devel,
linux-leds, devicetree, linux-kernel, linux-fbdev, imx,
linux-arm-kernel
In-Reply-To: <aKgboFjwjtZsanWb@aspen.lan>
On 8/22/25 09:26, Daniel Thompson wrote:
> On Tue, Aug 19, 2025 at 12:58:59PM +0200, Maud Spierings via B4 Relay wrote:
>> From: Maud Spierings <maudspierings@gocontroll.com>
>>
>> The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC
>> with intgrated boost controller.
>>
>> Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>
>> ---
>> .../bindings/leds/backlight/maxim,max25014.yaml | 79 ++++++++++++++++++++++
>> MAINTAINERS | 5 ++
>> 2 files changed, 84 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
>> new file mode 100644
>> index 0000000000000000000000000000000000000000..30b591152fa31d5e43243cac44c72028b05b5f8a
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
>> @@ -0,0 +1,79 @@
>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/leds/backlight/maxim,max25014.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Maxim max25014 backlight controller
>> +
>> +maintainers:
>> + - Maud Spierings <maudspierings@gocontroll.com>
>> +
>> +allOf:
>> + - $ref: common.yaml#
>> +
>> +properties:
>> + compatible:
>> + enum:
>> + - maxim,max25014
>> +
>> + reg:
>> + maxItems: 1
>> +
>> + enable-gpios:
>> + maxItems: 1
>> +
>> + interrupts:
>> + maxItems: 1
>
> Is the interrupt useful for anything?
>
> AFAIK its perfectly OK for DT bindings to describe hardware features the
> driver does not use... but is the driver missing out on error reporting
> (for example) by not using this interrupt for anything?
The interrupt is indeed for error reporting, it is not wired up in the
driver right now (although there is already a function for scanning the
error registers, I am not sure how I would properly hook that up to an
irq. This is my first driver so I thought to keep things simple for now,
these extra functions can be added later), same with the pwms for
example. But jeah I wanted to fully describe the hardware in the
bindings as from what I understand that is what should be done.
Kind regards,
Maud
^ permalink raw reply
* Re: [PATCH v2 2/4] backlight: add max25014atg backlight
From: Maud Spierings @ 2025-08-22 7:31 UTC (permalink / raw)
To: Daniel Thompson
Cc: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam, dri-devel,
linux-leds, devicetree, linux-kernel, linux-fbdev, imx,
linux-arm-kernel, MaudSpieringsmaudspierings
In-Reply-To: <aKgaUtcNoOsga6l7@aspen.lan>
Hi Daniel,
Thanks for the review!
On 8/22/25 09:20, Daniel Thompson wrote:
> On Tue, Aug 19, 2025 at 12:59:00PM +0200, Maud Spierings via B4 Relay wrote:
>> From: Maud Spierings <maudspierings@gocontroll.com>
>>
>> The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC
>> with intgrated boost controller.
>>
>> Signed-off-by: Maud Spierings maudspierings@gocontroll.com
>
> Looking good but still a few small comments (below).
>
>
>> diff --git a/drivers/video/backlight/max25014.c b/drivers/video/backlight/max25014.c
>> new file mode 100644
>> index 0000000000000000000000000000000000000000..fe5e0615cf6d151868b56ebb9544b175b09dfcee
>> --- /dev/null
>> +++ b/drivers/video/backlight/max25014.c
>> @@ -0,0 +1,395 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Backlight driver for Maxim MAX25014
>> + *
>> + * Copyright (C) 2025 GOcontroll B.V.
>> + * Author: Maud Spierings <maudspierings@gocontroll.com>
>> + */
>> +
>> +#include <linux/backlight.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/i2c.h>
>> +#include <linux/regmap.h>
>> +#include <linux/slab.h>
>> +
>> +#define MAX25014_ISET_DEFAULT_100 11
>> +#define MAX_BRIGHTNESS (100)
>> +#define MIN_BRIGHTNESS (0)
>> +#define TON_MAX (130720) /* @153Hz */
>> +#define TON_STEP (1307) /* @153Hz */
>> +#define TON_MIN (0)
>> +
>> +#define MAX25014_DEV_ID (0x00)
>> +#define MAX25014_REV_ID (0x01)
>> +#define MAX25014_ISET (0x02)
>> +#define MAX25014_IMODE (0x03)
>> +#define MAX25014_TON1H (0x04)
>> +#define MAX25014_TON1L (0x05)
>> +#define MAX25014_TON2H (0x06)
>> +#define MAX25014_TON2L (0x07)
>> +#define MAX25014_TON3H (0x08)
>> +#define MAX25014_TON3L (0x09)
>> +#define MAX25014_TON4H (0x0A)
>> +#define MAX25014_TON4L (0x0B)
>> +#define MAX25014_TON_1_4_LSB (0x0C)
>> +#define MAX25014_SETTING (0x12)
>> +#define MAX25014_DISABLE (0x13)
>> +#define MAX25014_BSTMON (0x14)
>> +#define MAX25014_IOUT1 (0x15)
>> +#define MAX25014_IOUT2 (0x16)
>> +#define MAX25014_IOUT3 (0x17)
>> +#define MAX25014_IOUT4 (0x18)
>> +#define MAX25014_OPEN (0x1B)
>> +#define MAX25014_SHORT_GND (0x1C)
>> +#define MAX25014_SHORT_LED (0x1D)
>> +#define MAX25014_MASK (0x1E)
>> +#define MAX25014_DIAG (0x1F)
>
> There is no need to put raw numbers in brackets.
gone in the next version, I'll also align the defines at the top better.
>> +
>> +#define MAX25014_IMODE_HDIM BIT(2)
>> +#define MAX25014_ISET_ENABLE BIT(5)
>> +#define MAX25014_ISET_PSEN BIT(4)
>> +#define MAX25014_DIAG_HW_RST BIT(2)
>> +#define MAX25014_SETTING_FPWM GENMASK(6, 4)
>> +
>> +struct max25014 {
>> + struct i2c_client *client;
>> + struct backlight_device *bl;
>> + struct regmap *regmap;
>> + struct max25014_platform_data *pdata;
>
> This appears to be unused.
oops forgot to remove that, how did it even build with that?
>> + struct gpio_desc *enable;
>> + struct regulator *vin; /* regulator for boost converter Vin rail */
>> + uint32_t initial_brightness;
>
> It is important to keep the initial_brightness for the lifetime of the
> driver?
I guess not, though I am not sure how to comfortably transport this
value to the max25014_configure() otherwise. Some temporary value that I
create in the probe function then pass as reference to
max25014_parse_dt() and then to max25014_configure()?
>> + uint32_t iset;
>> + uint8_t strings_mask;
>> +};
>> +
>
Kind regards,
Maud
^ permalink raw reply
* Re: [PATCH v2 1/4] dt-bindings: backlight: Add max25014 bindings
From: Daniel Thompson @ 2025-08-22 7:26 UTC (permalink / raw)
To: maudspierings
Cc: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam, dri-devel,
linux-leds, devicetree, linux-kernel, linux-fbdev, imx,
linux-arm-kernel
In-Reply-To: <20250819-max25014-v2-1-5fd7aeb141ea@gocontroll.com>
On Tue, Aug 19, 2025 at 12:58:59PM +0200, Maud Spierings via B4 Relay wrote:
> From: Maud Spierings <maudspierings@gocontroll.com>
>
> The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC
> with intgrated boost controller.
>
> Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>
> ---
> .../bindings/leds/backlight/maxim,max25014.yaml | 79 ++++++++++++++++++++++
> MAINTAINERS | 5 ++
> 2 files changed, 84 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..30b591152fa31d5e43243cac44c72028b05b5f8a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
> @@ -0,0 +1,79 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/backlight/maxim,max25014.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Maxim max25014 backlight controller
> +
> +maintainers:
> + - Maud Spierings <maudspierings@gocontroll.com>
> +
> +allOf:
> + - $ref: common.yaml#
> +
> +properties:
> + compatible:
> + enum:
> + - maxim,max25014
> +
> + reg:
> + maxItems: 1
> +
> + enable-gpios:
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 1
Is the interrupt useful for anything?
AFAIK its perfectly OK for DT bindings to describe hardware features the
driver does not use... but is the driver missing out on error reporting
(for example) by not using this interrupt for anything?
Daniel.
^ permalink raw reply
* Re: [PATCH v2 2/4] backlight: add max25014atg backlight
From: Daniel Thompson @ 2025-08-22 7:20 UTC (permalink / raw)
To: maudspierings
Cc: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam, dri-devel,
linux-leds, devicetree, linux-kernel, linux-fbdev, imx,
linux-arm-kernel, MaudSpieringsmaudspierings
In-Reply-To: <20250819-max25014-v2-2-5fd7aeb141ea@gocontroll.com>
On Tue, Aug 19, 2025 at 12:59:00PM +0200, Maud Spierings via B4 Relay wrote:
> From: Maud Spierings <maudspierings@gocontroll.com>
>
> The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC
> with intgrated boost controller.
>
> Signed-off-by: Maud Spierings maudspierings@gocontroll.com
Looking good but still a few small comments (below).
> diff --git a/drivers/video/backlight/max25014.c b/drivers/video/backlight/max25014.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..fe5e0615cf6d151868b56ebb9544b175b09dfcee
> --- /dev/null
> +++ b/drivers/video/backlight/max25014.c
> @@ -0,0 +1,395 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Backlight driver for Maxim MAX25014
> + *
> + * Copyright (C) 2025 GOcontroll B.V.
> + * Author: Maud Spierings <maudspierings@gocontroll.com>
> + */
> +
> +#include <linux/backlight.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +
> +#define MAX25014_ISET_DEFAULT_100 11
> +#define MAX_BRIGHTNESS (100)
> +#define MIN_BRIGHTNESS (0)
> +#define TON_MAX (130720) /* @153Hz */
> +#define TON_STEP (1307) /* @153Hz */
> +#define TON_MIN (0)
> +
> +#define MAX25014_DEV_ID (0x00)
> +#define MAX25014_REV_ID (0x01)
> +#define MAX25014_ISET (0x02)
> +#define MAX25014_IMODE (0x03)
> +#define MAX25014_TON1H (0x04)
> +#define MAX25014_TON1L (0x05)
> +#define MAX25014_TON2H (0x06)
> +#define MAX25014_TON2L (0x07)
> +#define MAX25014_TON3H (0x08)
> +#define MAX25014_TON3L (0x09)
> +#define MAX25014_TON4H (0x0A)
> +#define MAX25014_TON4L (0x0B)
> +#define MAX25014_TON_1_4_LSB (0x0C)
> +#define MAX25014_SETTING (0x12)
> +#define MAX25014_DISABLE (0x13)
> +#define MAX25014_BSTMON (0x14)
> +#define MAX25014_IOUT1 (0x15)
> +#define MAX25014_IOUT2 (0x16)
> +#define MAX25014_IOUT3 (0x17)
> +#define MAX25014_IOUT4 (0x18)
> +#define MAX25014_OPEN (0x1B)
> +#define MAX25014_SHORT_GND (0x1C)
> +#define MAX25014_SHORT_LED (0x1D)
> +#define MAX25014_MASK (0x1E)
> +#define MAX25014_DIAG (0x1F)
There is no need to put raw numbers in brackets.
> +
> +#define MAX25014_IMODE_HDIM BIT(2)
> +#define MAX25014_ISET_ENABLE BIT(5)
> +#define MAX25014_ISET_PSEN BIT(4)
> +#define MAX25014_DIAG_HW_RST BIT(2)
> +#define MAX25014_SETTING_FPWM GENMASK(6, 4)
> +
> +struct max25014 {
> + struct i2c_client *client;
> + struct backlight_device *bl;
> + struct regmap *regmap;
> + struct max25014_platform_data *pdata;
This appears to be unused.
> + struct gpio_desc *enable;
> + struct regulator *vin; /* regulator for boost converter Vin rail */
> + uint32_t initial_brightness;
It is important to keep the initial_brightness for the lifetime of the
driver?
> + uint32_t iset;
> + uint8_t strings_mask;
> +};
> +
Daniel.
^ permalink raw reply
* Re: UBSAN: shift-out-of-bounds in drivers/video/fbdev/core/fb_fillrect.h:100:21 (v6.17-rc2)
From: Kajtár Zsolt @ 2025-08-21 3:04 UTC (permalink / raw)
To: Erhard Furtner, linux-fbdev; +Cc: dri-devel
In-Reply-To: <1fda26b1-f988-449d-834d-b185d3ebf5c6@mailbox.org>
[-- Attachment #1.1: Type: text/plain, Size: 898 bytes --]
> Greetings!
>
> Getting this UBSAN hit on my PowerMac G4 DP with kernel 6.17-rc2:
>
> [...]
> Console: switching to colour frame buffer device 240x67
> ------------[ cut here ]------------
> UBSAN: shift-out-of-bounds in drivers/video/fbdev/core/fb_fillrect.h:100:21
> shift exponent 32 is too large for 32-bit type 'unsigned long'
Thanks for reporting!
> I guess this would be a problem on other 32bit arches too?
It's only on 32 bit big endian. I don't have UBSAN for MIPS on my setup
so haven't noticed it.
#ifndef __LITTLE_ENDIAN
pattern <<= (BITS_PER_LONG % bpp);
pattern |= pattern >> bpp; <-
#endif
In the 32 BPP case the result is identical in both the no shift and zero
result implementations.
I've patched it by skipping this realignment as it's only needed if the
BPP is smaller than the word length.
--
-soci-
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 495 bytes --]
^ permalink raw reply
* [PATCH] fbdev: core: fix ubsan warning in pixel_to_pat
From: Zsolt Kajtar @ 2025-08-21 2:42 UTC (permalink / raw)
To: linux-fbdev, dri-devel; +Cc: Zsolt Kajtar
It could be triggered on 32 bit big endian machines at 32 bpp in the
pattern realignment. In this case just return early as the result is
an identity.
Signed-off-by: Zsolt Kajtar <soci@c64.rulez.org>
---
drivers/video/fbdev/core/fb_fillrect.h | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/video/fbdev/core/fb_fillrect.h b/drivers/video/fbdev/core/fb_fillrect.h
index 66042e534..f366670a5 100644
--- a/drivers/video/fbdev/core/fb_fillrect.h
+++ b/drivers/video/fbdev/core/fb_fillrect.h
@@ -92,8 +92,7 @@ static unsigned long pixel_to_pat(int bpp, u32 color)
pattern = pattern | pattern << bpp;
break;
default:
- pattern = color;
- break;
+ return color;
}
#ifndef __LITTLE_ENDIAN
pattern <<= (BITS_PER_LONG % bpp);
--
2.30.2
^ permalink raw reply related
* UBSAN: shift-out-of-bounds in drivers/video/fbdev/core/fb_fillrect.h:100:21 (v6.17-rc2)
From: Erhard Furtner @ 2025-08-20 21:27 UTC (permalink / raw)
To: linux-fbdev; +Cc: dri-devel
Greetings!
Getting this UBSAN hit on my PowerMac G4 DP with kernel 6.17-rc2:
[...]
Console: switching to colour frame buffer device 240x67
------------[ cut here ]------------
UBSAN: shift-out-of-bounds in drivers/video/fbdev/core/fb_fillrect.h:100:21
shift exponent 32 is too large for 32-bit type 'unsigned long'
CPU: 1 UID: 0 PID: 542 Comm: (udev-worker) Tainted: G N
6.17.0-rc2-PMacG4 #2 PREEMPTLAZY
Tainted: [N]=TEST
Hardware name: PowerMac3,6 7455 0x80010303 PowerMac
Call Trace:
[c20fb270] [c0ac2494] __dump_stack+0x28/0x3c (unreliable)
[c20fb280] [c0ac244c] dump_stack_lvl+0x68/0x88
[c20fb2a0] [c0ac24c0] dump_stack+0x18/0x28
[c20fb2b0] [c06d8298] ubsan_epilogue+0x14/0x50
[c20fb2c0] [c06d7f3c] __ubsan_handle_shift_out_of_bounds+0x224/0x234
[c20fb350] [c07194b4] cfb_fillrect+0x9c4/0x9c8
[c20fb3c0] [c07181d4] bit_clear_margins+0xe8/0x108
[c20fb400] [c0714a0c] fbcon_clear_margins+0xa0/0xd8
[c20fb420] [c0715ce0] fbcon_switch+0x3c0/0x510
[c20fb500] [c0743934] redraw_screen+0x134/0x200
[c20fb530] [c0745ab0] do_bind_con_driver+0x41c/0x458
[c20fb590] [c0745eb0] do_take_over_console+0x18c/0x1e4
[c20fb5c0] [c0713f90] do_fbcon_takeover+0xf8/0x1bc
[c20fb5f0] [c0712bec] fbcon_fb_registered+0x1e8/0x2a8
[c20fb620] [c070e0bc] register_framebuffer+0x22c/0x2d0
[c20fb680] [beb146f4]
__drm_fb_helper_initial_config_and_unlock+0x4b0/0x674 [drm_kms_helper]
[c20fb700] [beb14218] drm_fb_helper_initial_config+0x44/0x70
[drm_kms_helper]
[c20fb720] [beb413c4] drm_fbdev_client_hotplug+0x90/0x104 [drm_client_lib]
[c20fb740] [c07ac3c4] drm_client_register+0x90/0xfc
[c20fb770] [beb4114c] drm_fbdev_client_setup+0x110/0x278 [drm_client_lib]
[c20fb790] [beb40278] drm_client_setup+0xc0/0x134 [drm_client_lib]
[c20fb7a0] [bebaa494] radeon_pci_probe+0x220/0x228 [radeon]
[c20fb7c0] [c06eee78] pci_device_probe+0xc4/0x190
[c20fb7f0] [c07c309c] really_probe+0xf4/0x2d8
[c20fb810] [c07c24c8] __driver_probe_device+0xa4/0x114
[c20fb830] [c07c2f0c] driver_probe_device+0x4c/0xe8
[c20fb850] [c07c26b0] __driver_attach+0xcc/0x128
[c20fb870] [c07bfc38] bus_for_each_dev+0xa4/0xe8
[c20fb8a0] [c07c25d4] driver_attach+0x24/0x34
[c20fb8b0] [c07c0380] bus_add_driver+0x20c/0x2e0
[c20fb8e0] [c07c3d4c] driver_register+0x8c/0x154
[c20fb900] [c06eeaa8] __pci_register_driver+0x74/0x88
[c20fb910] [beba60bc] init_module+0x8c/0xfd0 [radeon]
[c20fb920] [c0007958] do_one_initcall+0xf0/0x2d8
[c20fbc10] [c00fdf08] do_init_module+0x90/0x33c
[c20fbc30] [c00fd0cc] load_module+0x1428/0x14bc
[c20fbc80] [c00fafac] sys_finit_module+0x250/0x350
[c20fbd40] [c0012d60] system_call_exception+0xe0/0x204
[c20fbf30] [c00181ac] ret_from_syscall+0x0/0x2c
---- interrupt: c00 at 0x43fc94
NIP: 0043fc94 LR: 0054c254 CTR: 00453790
REGS: c20fbf40 TRAP: 0c00 Tainted: G N
(6.17.0-rc2-PMacG4)
MSR: 0000d032 <EE,PR,ME,IR,DR,RI> CR: 2822242c XER: 20000000
GPR00: 00000161 af93bb50 a7ae5880 00000023 005583e8 00000000 af93bb25
0000007f
GPR08: 00000000 00000000 0000002f 0a565c56 4422842c 00a9f71c 2822442c
00000000
GPR16: 00020000 0aba9500 00000000 00000000 010b1dc0 00000000 010b86c0
af93bd3c
GPR24: 010b1dc0 00000000 00020000 010a6400 005583e8 00000000 00577ad0
010b1dc0
NIP [0043fc94] 0x43fc94
LR [0054c254] 0x54c254
---- interrupt: c00
---[ end trace ]---
ADM1030 fan controller [@2c]
DS1775 digital thermometer [@49]
radeon 0000:00:10.0: [drm] fb0: radeondrmfb frame buffer device
[...]
I guess this would be a problem on other 32bit arches too?
If needed I can attach full dmesg, kernel .config lspci output.
Regards,
Erhard
^ permalink raw reply
* Re: [PATCH 2/9] fbdev: Use panic_in_progress() helper
From: Qianqiang Liu @ 2025-08-20 10:44 UTC (permalink / raw)
To: Jinchao Wang
Cc: pmladek, akpm, Simona Vetter, Helge Deller, Thomas Zimmermann,
Ville Syrjälä, Shixiong Ou, Sravan Kumar Gundu,
Zsolt Kajtar, Kees Cook, linux-kernel, feng.tang, joel.granados,
john.ogness, namcao, linux-fbdev, dri-devel
In-Reply-To: <20250820091702.512524-3-wangjinchao600@gmail.com>
On Wed, Aug 20, 2025 at 05:14:47PM +0800, Jinchao Wang wrote:
> This patch updates the fbcon_skip_panic() function to use
> the panic_in_progress() helper.
>
> The previous direct access to panic_cpu is less
> readable and is being replaced by a dedicated function
> that more clearly expresses the intent.
>
> This change is part of a series to refactor the kernel's
> panic handling logic for better clarity and robustness.
>
> Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com>
> ---
> drivers/video/fbdev/core/fbcon.c | 9 +--------
> 1 file changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
> index 55f5731e94c3..b062b05f4128 100644
> --- a/drivers/video/fbdev/core/fbcon.c
> +++ b/drivers/video/fbdev/core/fbcon.c
> @@ -279,14 +279,7 @@ static int fbcon_get_rotate(struct fb_info *info)
>
> static bool fbcon_skip_panic(struct fb_info *info)
> {
> -/* panic_cpu is not exported, and can't be used if built as module. Use
> - * oops_in_progress instead, but non-fatal oops won't be printed.
> - */
> -#if defined(MODULE)
> - return (info->skip_panic && unlikely(oops_in_progress));
> -#else
> - return (info->skip_panic && unlikely(atomic_read(&panic_cpu) != PANIC_CPU_INVALID));
> -#endif
> + return (info->skip_panic && unlikely(panic_in_progress()));
> }
>
> static inline bool fbcon_is_active(struct vc_data *vc, struct fb_info *info)
> --
> 2.43.0
Acked-by Qianqiang Liu <qianqiang.liu@163.com>
--
Best,
Qianqiang Liu
^ permalink raw reply
* [PATCH 2/9] fbdev: Use panic_in_progress() helper
From: Jinchao Wang @ 2025-08-20 9:14 UTC (permalink / raw)
To: pmladek, akpm, Simona Vetter, Helge Deller, Thomas Zimmermann,
Ville Syrjälä, Qianqiang Liu, Shixiong Ou, Jinchao Wang,
Sravan Kumar Gundu, Zsolt Kajtar, Kees Cook
Cc: linux-kernel, feng.tang, joel.granados, john.ogness, namcao,
linux-fbdev, dri-devel
In-Reply-To: <20250820091702.512524-2-wangjinchao600@gmail.com>
This patch updates the fbcon_skip_panic() function to use
the panic_in_progress() helper.
The previous direct access to panic_cpu is less
readable and is being replaced by a dedicated function
that more clearly expresses the intent.
This change is part of a series to refactor the kernel's
panic handling logic for better clarity and robustness.
Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com>
---
drivers/video/fbdev/core/fbcon.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 55f5731e94c3..b062b05f4128 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -279,14 +279,7 @@ static int fbcon_get_rotate(struct fb_info *info)
static bool fbcon_skip_panic(struct fb_info *info)
{
-/* panic_cpu is not exported, and can't be used if built as module. Use
- * oops_in_progress instead, but non-fatal oops won't be printed.
- */
-#if defined(MODULE)
- return (info->skip_panic && unlikely(oops_in_progress));
-#else
- return (info->skip_panic && unlikely(atomic_read(&panic_cpu) != PANIC_CPU_INVALID));
-#endif
+ return (info->skip_panic && unlikely(panic_in_progress()));
}
static inline bool fbcon_is_active(struct vc_data *vc, struct fb_info *info)
--
2.43.0
^ permalink raw reply related
* Re: [PATCH v2 1/4] dt-bindings: backlight: Add max25014 bindings
From: Maud Spierings @ 2025-08-20 5:19 UTC (permalink / raw)
To: Rob Herring
Cc: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam, dri-devel,
linux-leds, devicetree, linux-kernel, linux-fbdev, imx,
linux-arm-kernel
In-Reply-To: <20250819195008.GA1218175-robh@kernel.org>
On 8/19/25 21:50, Rob Herring wrote:
> On Tue, Aug 19, 2025 at 12:58:59PM +0200, Maud Spierings wrote:
>> The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC
>> with intgrated boost controller.
>>
>> Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>
>> ---
>> .../bindings/leds/backlight/maxim,max25014.yaml | 79 ++++++++++++++++++++++
>> MAINTAINERS | 5 ++
>> 2 files changed, 84 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
>> new file mode 100644
>> index 0000000000000000000000000000000000000000..30b591152fa31d5e43243cac44c72028b05b5f8a
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
>> @@ -0,0 +1,79 @@
>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/leds/backlight/maxim,max25014.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Maxim max25014 backlight controller
>> +
>> +maintainers:
>> + - Maud Spierings <maudspierings@gocontroll.com>
>> +
>> +allOf:
>> + - $ref: common.yaml#
>> +
>> +properties:
>> + compatible:
>> + enum:
>> + - maxim,max25014
>> +
>> + reg:
>> + maxItems: 1
>> +
>> + enable-gpios:
>> + maxItems: 1
>> +
>> + interrupts:
>> + maxItems: 1
>> +
>> + power-supply:
>> + description: Regulator which controls the boost converter input rail.
>> +
>> + pwms:
>> + maxItems: 1
>> +
>> + maxim,iset:
>> + $ref: /schemas/types.yaml#/definitions/uint32
>
> maximum: 15
done
>> + default: 11
>> + description:
>> + Value of the ISET register field (0-15).
>
> Perhaps a little on what this controls?
done, for now, it controls the current scale of the backlight, higher
number = more current. But I will put it in the description in v3
>> +
>> + maxim,strings:
>> + $ref: /schemas/types.yaml#/definitions/uint32-array
>> + description:
>> + A 4-bit bitfield that describes which led strings to turn on.
>> + minItems: 4
>> + maxItems: 4
>
> items:
> maximum: 1
>
> But why not just an 8-bit value 0x0-0xF?
That is possible too, the logic is inverted in the actual chip, a bit
set means the string is turned off, but that can be solved with a
bitwise not. This just felt like a natural way to read/edit it, an 8-bit
value you have to first translate the bits into a hex value which isn't
very clear about what it is actually doing.
Is it possible to to 0b0111 notation in a devicetree? That would make it
better at least.
>> +
>> +required:
>> + - compatible
>> + - reg
>> + - maxim,strings
>> +
>> +unevaluatedProperties: false
>> +
>> +examples:
>> + - |
>> + #include <dt-bindings/gpio/gpio.h>
>> + #include <dt-bindings/interrupt-controller/irq.h>
>> +
>> + i2c {
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> +
>> + backlight: backlight@6f {
>
> Drop unused labels.
oops dropped
>> + reg = <0x6f>;
>> + compatible = "maxim,max25014";
>
> compatible is always first.
Messed that up in the dtsos too, fixed everywhere in v3
>> + default-brightness = <50>;
>> + enable-gpios = <&gpio1 4 GPIO_ACTIVE_HIGH>;
>> + interrupt-parent = <&gpio1>;
>> + interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
>> + pinctrl-names = "default";
>> + pinctrl-0 = <&pinctrl_backlight>;
>
> Generally we don't put pinctrl properties in examples as they are always
> allowed.
dropped
>> + power-supply = <®_backlight>;
>> + pwms = <&pwm1>;
>> + maxim,iset = <7>;
>> + maxim,strings = <1 1 1 1>;
>> + };
>> + };
>> +
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index e81d5f9fbd16cc384356804390d65652bbb9e3f6..11c73d2e37fac22aea852152746236c1472f41b8 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -14972,6 +14972,11 @@ F: Documentation/userspace-api/media/drivers/max2175.rst
>> F: drivers/media/i2c/max2175*
>> F: include/uapi/linux/max2175.h
>>
>> +MAX25014 BACKLIGHT DRIVER
>> +M: Maud Spierings <maudspierings@gocontroll.com>
>> +S: Maintained
>> +F: Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
>> +
>> MAX31335 RTC DRIVER
>> M: Antoniu Miclaus <antoniu.miclaus@analog.com>
>> L: linux-rtc@vger.kernel.org
>>
>> --
>> 2.50.1
>>
Thanks for your review!
Kind regards,
Maud
^ permalink raw reply
* Re: [PATCH v2 1/4] dt-bindings: backlight: Add max25014 bindings
From: Rob Herring @ 2025-08-19 19:50 UTC (permalink / raw)
To: Maud Spierings
Cc: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam, dri-devel,
linux-leds, devicetree, linux-kernel, linux-fbdev, imx,
linux-arm-kernel
In-Reply-To: <20250819-max25014-v2-1-5fd7aeb141ea@gocontroll.com>
On Tue, Aug 19, 2025 at 12:58:59PM +0200, Maud Spierings wrote:
> The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC
> with intgrated boost controller.
>
> Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>
> ---
> .../bindings/leds/backlight/maxim,max25014.yaml | 79 ++++++++++++++++++++++
> MAINTAINERS | 5 ++
> 2 files changed, 84 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..30b591152fa31d5e43243cac44c72028b05b5f8a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
> @@ -0,0 +1,79 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/backlight/maxim,max25014.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Maxim max25014 backlight controller
> +
> +maintainers:
> + - Maud Spierings <maudspierings@gocontroll.com>
> +
> +allOf:
> + - $ref: common.yaml#
> +
> +properties:
> + compatible:
> + enum:
> + - maxim,max25014
> +
> + reg:
> + maxItems: 1
> +
> + enable-gpios:
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 1
> +
> + power-supply:
> + description: Regulator which controls the boost converter input rail.
> +
> + pwms:
> + maxItems: 1
> +
> + maxim,iset:
> + $ref: /schemas/types.yaml#/definitions/uint32
maximum: 15
> + default: 11
> + description:
> + Value of the ISET register field (0-15).
Perhaps a little on what this controls?
> +
> + maxim,strings:
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + description:
> + A 4-bit bitfield that describes which led strings to turn on.
> + minItems: 4
> + maxItems: 4
items:
maximum: 1
But why not just an 8-bit value 0x0-0xF?
> +
> +required:
> + - compatible
> + - reg
> + - maxim,strings
> +
> +unevaluatedProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> + #include <dt-bindings/interrupt-controller/irq.h>
> +
> + i2c {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + backlight: backlight@6f {
Drop unused labels.
> + reg = <0x6f>;
> + compatible = "maxim,max25014";
compatible is always first.
> + default-brightness = <50>;
> + enable-gpios = <&gpio1 4 GPIO_ACTIVE_HIGH>;
> + interrupt-parent = <&gpio1>;
> + interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
> + pinctrl-names = "default";
> + pinctrl-0 = <&pinctrl_backlight>;
Generally we don't put pinctrl properties in examples as they are always
allowed.
> + power-supply = <®_backlight>;
> + pwms = <&pwm1>;
> + maxim,iset = <7>;
> + maxim,strings = <1 1 1 1>;
> + };
> + };
> +
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e81d5f9fbd16cc384356804390d65652bbb9e3f6..11c73d2e37fac22aea852152746236c1472f41b8 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -14972,6 +14972,11 @@ F: Documentation/userspace-api/media/drivers/max2175.rst
> F: drivers/media/i2c/max2175*
> F: include/uapi/linux/max2175.h
>
> +MAX25014 BACKLIGHT DRIVER
> +M: Maud Spierings <maudspierings@gocontroll.com>
> +S: Maintained
> +F: Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
> +
> MAX31335 RTC DRIVER
> M: Antoniu Miclaus <antoniu.miclaus@analog.com>
> L: linux-rtc@vger.kernel.org
>
> --
> 2.50.1
>
^ permalink raw reply
* [syzbot] [fbdev?] KASAN: slab-out-of-bounds Read in fb_pad_aligned_buffer (2)
From: syzbot @ 2025-08-19 15:42 UTC (permalink / raw)
To: deller, dri-devel, linux-fbdev, linux-kernel, simona,
syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: 2674d1eadaa2 Add linux-next specific files for 20250812
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10c12af0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=712e4169f26d539a
dashboard link: https://syzkaller.appspot.com/bug?extid=ef4f385c7132a39eabb2
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d6fec408ef67/disk-2674d1ea.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/27b3f312fa12/vmlinux-2674d1ea.xz
kernel image: https://storage.googleapis.com/syzbot-assets/56e7b0c45a7e/bzImage-2674d1ea.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ef4f385c7132a39eabb2@syzkaller.appspotmail.com
overlayfs: conflicting options: nfs_export=on,metacopy=on
==================================================================
BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:641 [inline]
BUG: KASAN: slab-out-of-bounds in fb_pad_aligned_buffer+0x57e/0x5f0 drivers/video/fbdev/core/fbmem.c:96
Read of size 1 at addr ffff8880593d7a10 by task syz.6.4465/21843
CPU: 1 UID: 0 PID: 21843 Comm: syz.6.4465 Not tainted 6.17.0-rc1-next-20250812-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xca/0x240 mm/kasan/report.c:482
kasan_report+0x118/0x150 mm/kasan/report.c:595
__fb_pad_aligned_buffer include/linux/fb.h:641 [inline]
fb_pad_aligned_buffer+0x57e/0x5f0 drivers/video/fbdev/core/fbmem.c:96
bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:98 [inline]
bit_putcs+0x1648/0x1a50 drivers/video/fbdev/core/bitblit.c:184
fbcon_putcs+0x3e5/0x5f0 drivers/video/fbdev/core/fbcon.c:1327
do_update_region+0x21c/0x440 drivers/tty/vt/vt.c:617
update_region+0x1ce/0x490 drivers/tty/vt/vt.c:641
vcs_write+0xd65/0x1260 drivers/tty/vt/vc_screen.c:698
do_loop_readv_writev fs/read_write.c:850 [inline]
vfs_writev+0x4b6/0x960 fs/read_write.c:1059
do_writev+0x14d/0x2d0 fs/read_write.c:1103
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f68db78ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f68dc5ed038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f68db9b5fa0 RCX: 00007f68db78ebe9
RDX: 000000000000000e RSI: 0000200000000c40 RDI: 0000000000000004
RBP: 00007f68db811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f68db9b6038 R14: 00007f68db9b5fa0 R15: 00007fff61c4c208
</TASK>
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880593d7a80 pfn:0x593d4
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f8(unknown)
raw: 00fff00000000040 0000000000000000 dead000000000122 0000000000000000
raw: ffff8880593d7a80 0000000000000000 00000000f8000000 0000000000000000
head: 00fff00000000040 0000000000000000 dead000000000122 0000000000000000
head: ffff8880593d7a80 0000000000000000 00000000f8000000 0000000000000000
head: 00fff00000000002 ffffea000164f501 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x140cc0(GFP_USER|__GFP_COMP), pid 19098, tgid 19083 (syz.1.3690), ts 809460860721, free_ts 809191260089
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
prep_new_page mm/page_alloc.c:1859 [inline]
get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
___kmalloc_large_node+0x5f/0x1b0 mm/slub.c:4306
__kmalloc_large_node_noprof+0x18/0x90 mm/slub.c:4337
__do_kmalloc_node mm/slub.c:4353 [inline]
__kmalloc_noprof+0x36f/0x4f0 mm/slub.c:4377
kmalloc_noprof include/linux/slab.h:909 [inline]
fbcon_set_font+0x519/0xe90 drivers/video/fbdev/core/fbcon.c:2536
con_font_set drivers/tty/vt/vt.c:4887 [inline]
con_font_op+0xcac/0x1070 drivers/tty/vt/vt.c:4934
vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]
vt_ioctl+0x1a8a/0x1f00 drivers/tty/vt/vt_ioctl.c:751
tty_ioctl+0x926/0xde0 drivers/tty/tty_io.c:2792
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:598 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 19061 tgid 19060 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
discard_slab mm/slub.c:2753 [inline]
__put_partials+0x156/0x1a0 mm/slub.c:3218
put_cpu_partial+0x17c/0x250 mm/slub.c:3293
__slab_free+0x2d5/0x3c0 mm/slub.c:4550
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4180 [inline]
slab_alloc_node mm/slub.c:4229 [inline]
__do_kmalloc_node mm/slub.c:4364 [inline]
__kmalloc_noprof+0x224/0x4f0 mm/slub.c:4377
kmalloc_noprof include/linux/slab.h:909 [inline]
tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_number_perm+0x1e8/0x5a0 security/tomoyo/file.c:723
security_file_ioctl+0xcb/0x2d0 security/security.c:2982
__do_sys_ioctl fs/ioctl.c:592 [inline]
__se_sys_ioctl+0x47/0x170 fs/ioctl.c:584
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff8880593d7900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880593d7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880593d7a00: 00 00 fe fe fe fe fe fe fe fe fe fe fe fe fe fe
^
ffff8880593d7a80: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
ffff8880593d7b00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
^ permalink raw reply
* Re: [PATCH] backlight: led_bl: Use devm_kcalloc() for array space allocation
From: Qianfeng Rong @ 2025-08-19 13:29 UTC (permalink / raw)
To: Daniel Thompson
Cc: Lee Jones, Daniel Thompson, Jingoo Han, Helge Deller, dri-devel,
linux-fbdev, linux-kernel
In-Reply-To: <aKR6FAYDrNDhY6Af@aspen.lan>
在 2025/8/19 21:20, Daniel Thompson 写道:
> [You don't often get email from daniel@riscstar.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
>
> On Tue, Aug 19, 2025 at 11:58:03AM +0800, Qianfeng Rong wrote:
>> Replace calls of devm_kzalloc() with devm_kcalloc() in led_bl_get_leds()
>> and led_bl_parse_levels() for safer memory allocation with built-in
>> overflow protection.
>> Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
>> ---
> I assume you scanned drivers/video/backlight to look for similar code
> patterns in other backlight drivers? If you did it would have been
> really helpful to say so in this part of the patch (because in it's
> absence I had to do that myself).
Yes, I scanned the entire system and there was only this one in
drivers/video/backlight.
>
> However, the code changes are fine:
> Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>
>
Best regards,
Qianfeng
^ permalink raw reply
* Re: [PATCH] backlight: led_bl: Use devm_kcalloc() for array space allocation
From: Daniel Thompson @ 2025-08-19 13:20 UTC (permalink / raw)
To: Qianfeng Rong
Cc: Lee Jones, Daniel Thompson, Jingoo Han, Helge Deller, dri-devel,
linux-fbdev, linux-kernel
In-Reply-To: <20250819035804.433615-1-rongqianfeng@vivo.com>
On Tue, Aug 19, 2025 at 11:58:03AM +0800, Qianfeng Rong wrote:
> Replace calls of devm_kzalloc() with devm_kcalloc() in led_bl_get_leds()
> and led_bl_parse_levels() for safer memory allocation with built-in
> overflow protection.
>
> Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
> ---
I assume you scanned drivers/video/backlight to look for similar code
patterns in other backlight drivers? If you did it would have been
really helpful to say so in this part of the patch (because in it's
absence I had to do that myself).
However, the code changes are fine:
Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>
Daniel.
^ permalink raw reply
* Re: [PATCH v2 1/4] dt-bindings: backlight: Add max25014 bindings
From: Maud Spierings @ 2025-08-19 12:35 UTC (permalink / raw)
To: Fabio Estevam
Cc: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, dri-devel, linux-leds,
devicetree, linux-kernel, linux-fbdev, imx, linux-arm-kernel
In-Reply-To: <CAOMZO5D6m3V2ZpFOtabrkvf6+SGE+3-xpAE=PZo+Ak=49ozyLg@mail.gmail.com>
On 8/19/25 14:28, Fabio Estevam wrote:
> On Tue, Aug 19, 2025 at 7:59 AM Maud Spierings via B4 Relay
> <devnull+maudspierings.gocontroll.com@kernel.org> wrote:
>>
>> From: Maud Spierings <maudspierings@gocontroll.com>
>>
>> The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC
>> with intgrated boost controller.
>
> Typo: integrated
oopsie fixed, ctrl+c ctrl+v in patch 2 fixed too
^ permalink raw reply
* Re: [PATCH v2 1/4] dt-bindings: backlight: Add max25014 bindings
From: Rob Herring (Arm) @ 2025-08-19 12:32 UTC (permalink / raw)
To: Maud Spierings
Cc: imx, Krzysztof Kozlowski, devicetree, linux-fbdev, Lee Jones,
Jingoo Han, Shawn Guo, dri-devel, linux-kernel,
Pengutronix Kernel Team, Daniel Thompson, Pavel Machek,
Conor Dooley, Fabio Estevam, Sascha Hauer, linux-arm-kernel,
linux-leds, Helge Deller
In-Reply-To: <20250819-max25014-v2-1-5fd7aeb141ea@gocontroll.com>
On Tue, 19 Aug 2025 12:58:59 +0200, Maud Spierings wrote:
> The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC
> with intgrated boost controller.
>
> Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>
> ---
> .../bindings/leds/backlight/maxim,max25014.yaml | 79 ++++++++++++++++++++++
> MAINTAINERS | 5 ++
> 2 files changed, 84 insertions(+)
>
My bot found errors running 'make dt_binding_check' on your patch:
yamllint warnings/errors:
dtschema/dtc warnings/errors:
doc reference errors (make refcheckdocs):
See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20250819-max25014-v2-1-5fd7aeb141ea@gocontroll.com
The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.
If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:
pip3 install dtschema --upgrade
Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.
^ permalink raw reply
* Re: [PATCH v2 1/4] dt-bindings: backlight: Add max25014 bindings
From: Fabio Estevam @ 2025-08-19 12:28 UTC (permalink / raw)
To: maudspierings
Cc: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, dri-devel, linux-leds,
devicetree, linux-kernel, linux-fbdev, imx, linux-arm-kernel
In-Reply-To: <20250819-max25014-v2-1-5fd7aeb141ea@gocontroll.com>
On Tue, Aug 19, 2025 at 7:59 AM Maud Spierings via B4 Relay
<devnull+maudspierings.gocontroll.com@kernel.org> wrote:
>
> From: Maud Spierings <maudspierings@gocontroll.com>
>
> The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC
> with intgrated boost controller.
Typo: integrated
^ permalink raw reply
* [PATCH v2 3/4] arm64: dts: freescale: moduline-display-av101hdt-a10: add backlight
From: Maud Spierings via B4 Relay @ 2025-08-19 10:59 UTC (permalink / raw)
To: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam
Cc: dri-devel, linux-leds, devicetree, linux-kernel, linux-fbdev, imx,
linux-arm-kernel, Maud Spierings
In-Reply-To: <20250819-max25014-v2-0-5fd7aeb141ea@gocontroll.com>
From: Maud Spierings <maudspierings@gocontroll.com>
Add the missing backlight driver.
Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>
---
...tx8p-ml81-moduline-display-106-av101hdt-a10.dtso | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/arch/arm64/boot/dts/freescale/imx8mp-tx8p-ml81-moduline-display-106-av101hdt-a10.dtso b/arch/arm64/boot/dts/freescale/imx8mp-tx8p-ml81-moduline-display-106-av101hdt-a10.dtso
index e3965caca6be42a17aa89b77bd5b919382c84151..143243ba95cd7a69c7b043fa0fb32c37b67e1064 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp-tx8p-ml81-moduline-display-106-av101hdt-a10.dtso
+++ b/arch/arm64/boot/dts/freescale/imx8mp-tx8p-ml81-moduline-display-106-av101hdt-a10.dtso
@@ -17,6 +17,7 @@
panel {
compatible = "boe,av101hdt-a10";
+ backlight = <&backlight>;
enable-gpios = <&gpio1 7 GPIO_ACTIVE_HIGH>;
pinctrl-0 = <&pinctrl_panel>;
pinctrl-names = "default";
@@ -40,7 +41,27 @@ reg_vbus: regulator-vbus {
};
};
+&i2c4 {
+ backlight: backlight@6f {
+ reg = <0x6f>;
+ compatible = "maxim,max25014";
+ default-brightness = <50>;
+ enable-gpios = <&gpio1 4 GPIO_ACTIVE_HIGH>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_backlight>;
+ maxim,iset = <7>;
+ maxim,strings = <1 1 1 0>;
+ };
+};
+
&iomuxc {
+ pinctrl_backlight: backlightgrp {
+ fsl,pins = <
+ MX8MP_IOMUXC_GPIO1_IO04__GPIO1_IO04
+ (MX8MP_PULL_UP | MX8MP_PULL_ENABLE)
+ >;
+ };
+
pinctrl_panel: panelgrp {
fsl,pins = <
MX8MP_IOMUXC_GPIO1_IO07__GPIO1_IO07
--
2.50.1
^ permalink raw reply related
* [PATCH v2 4/4] arm64: dts: freescale: moduline-display-av123z7m-n17: add backlight
From: Maud Spierings via B4 Relay @ 2025-08-19 10:59 UTC (permalink / raw)
To: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam
Cc: dri-devel, linux-leds, devicetree, linux-kernel, linux-fbdev, imx,
linux-arm-kernel, Maud Spierings
In-Reply-To: <20250819-max25014-v2-0-5fd7aeb141ea@gocontroll.com>
From: Maud Spierings <maudspierings@gocontroll.com>
Add the missing backlight.
Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>
---
...p-tx8p-ml81-moduline-display-106-av123z7m-n17.dtso | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/boot/dts/freescale/imx8mp-tx8p-ml81-moduline-display-106-av123z7m-n17.dtso b/arch/arm64/boot/dts/freescale/imx8mp-tx8p-ml81-moduline-display-106-av123z7m-n17.dtso
index 3eb665ce9d5d2a1c742ffb4feca046e406e29956..9124cd87cce54a5aa7b7ad674f70f814d1dc3515 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp-tx8p-ml81-moduline-display-106-av123z7m-n17.dtso
+++ b/arch/arm64/boot/dts/freescale/imx8mp-tx8p-ml81-moduline-display-106-av123z7m-n17.dtso
@@ -16,6 +16,7 @@
panel {
compatible = "boe,av123z7m-n17";
+ backlight = <&backlight>;
enable-gpios = <&gpio1 7 GPIO_ACTIVE_HIGH>;
pinctrl-0 = <&pinctrl_panel>;
pinctrl-names = "default";
@@ -91,10 +92,26 @@ lvds1_out: endpoint {
};
};
- /* max25014 @ 0x6f */
+ backlight: backlight@6f {
+ reg = <0x6f>;
+ compatible = "maxim,max25014";
+ default-brightness = <50>;
+ enable-gpios = <&gpio1 4 GPIO_ACTIVE_HIGH>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_backlight>;
+ maxim,iset = <7>;
+ maxim,strings = <1 1 1 1>;
+ };
};
&iomuxc {
+ pinctrl_backlight: backlightgrp {
+ fsl,pins = <
+ MX8MP_IOMUXC_GPIO1_IO04__GPIO1_IO04
+ (MX8MP_PULL_UP | MX8MP_PULL_ENABLE)
+ >;
+ };
+
pinctrl_lvds_bridge: lvdsbridgegrp {
fsl,pins = <
MX8MP_IOMUXC_SAI1_TXD2__GPIO4_IO14
--
2.50.1
^ permalink raw reply related
* [PATCH v2 2/4] backlight: add max25014atg backlight
From: Maud Spierings via B4 Relay @ 2025-08-19 10:59 UTC (permalink / raw)
To: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam
Cc: dri-devel, linux-leds, devicetree, linux-kernel, linux-fbdev, imx,
linux-arm-kernel, Maud Spierings,
"Maud Spierings maudspierings"
In-Reply-To: <20250819-max25014-v2-0-5fd7aeb141ea@gocontroll.com>
From: Maud Spierings <maudspierings@gocontroll.com>
The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC
with intgrated boost controller.
Signed-off-by: Maud Spierings maudspierings@gocontroll.com
---
MAINTAINERS | 1 +
drivers/video/backlight/Kconfig | 7 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/max25014.c | 395 +++++++++++++++++++++++++++++++++++++
4 files changed, 404 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 11c73d2e37fac22aea852152746236c1472f41b8..d5b75af7e776e7e30e057eea5b49bb8a266e4963 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14976,6 +14976,7 @@ MAX25014 BACKLIGHT DRIVER
M: Maud Spierings <maudspierings@gocontroll.com>
S: Maintained
F: Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
+F: drivers/video/backlight/max25014.c
MAX31335 RTC DRIVER
M: Antoniu Miclaus <antoniu.miclaus@analog.com>
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index d9374d208ceebbf8b3c27976e9cb4d725939b942..d3bb6ccd41853d940f24c6ab8135e4b9b9ebefd7 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -262,6 +262,13 @@ config BACKLIGHT_DA9052
help
Enable the Backlight Driver for DA9052-BC and DA9053-AA/Bx PMICs.
+config BACKLIGHT_MAX25014
+ tristate "Backlight driver for the Maxim MAX25014 chip"
+ depends on I2C
+ select REGMAP_I2C
+ help
+ If you are using a MAX25014 chip as a backlight driver say Y to enable it.
+
config BACKLIGHT_MAX8925
tristate "Backlight driver for MAX8925"
depends on MFD_MAX8925
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index dfbb169bf6ea215704859f633b6c4a887f4ebacd..1170d9ec40b8dbd52aeec1dade1cd2d2b56af466 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -45,6 +45,7 @@ obj-$(CONFIG_BACKLIGHT_LOCOMO) += locomolcd.o
obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o
obj-$(CONFIG_BACKLIGHT_LP8788) += lp8788_bl.o
obj-$(CONFIG_BACKLIGHT_LV5207LP) += lv5207lp.o
+obj-$(CONFIG_BACKLIGHT_MAX25014) += max25014.o
obj-$(CONFIG_BACKLIGHT_MAX8925) += max8925_bl.o
obj-$(CONFIG_BACKLIGHT_MP3309C) += mp3309c.o
obj-$(CONFIG_BACKLIGHT_MT6370) += mt6370-backlight.o
diff --git a/drivers/video/backlight/max25014.c b/drivers/video/backlight/max25014.c
new file mode 100644
index 0000000000000000000000000000000000000000..fe5e0615cf6d151868b56ebb9544b175b09dfcee
--- /dev/null
+++ b/drivers/video/backlight/max25014.c
@@ -0,0 +1,395 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Backlight driver for Maxim MAX25014
+ *
+ * Copyright (C) 2025 GOcontroll B.V.
+ * Author: Maud Spierings <maudspierings@gocontroll.com>
+ */
+
+#include <linux/backlight.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define MAX25014_ISET_DEFAULT_100 11
+#define MAX_BRIGHTNESS (100)
+#define MIN_BRIGHTNESS (0)
+#define TON_MAX (130720) /* @153Hz */
+#define TON_STEP (1307) /* @153Hz */
+#define TON_MIN (0)
+
+#define MAX25014_DEV_ID (0x00)
+#define MAX25014_REV_ID (0x01)
+#define MAX25014_ISET (0x02)
+#define MAX25014_IMODE (0x03)
+#define MAX25014_TON1H (0x04)
+#define MAX25014_TON1L (0x05)
+#define MAX25014_TON2H (0x06)
+#define MAX25014_TON2L (0x07)
+#define MAX25014_TON3H (0x08)
+#define MAX25014_TON3L (0x09)
+#define MAX25014_TON4H (0x0A)
+#define MAX25014_TON4L (0x0B)
+#define MAX25014_TON_1_4_LSB (0x0C)
+#define MAX25014_SETTING (0x12)
+#define MAX25014_DISABLE (0x13)
+#define MAX25014_BSTMON (0x14)
+#define MAX25014_IOUT1 (0x15)
+#define MAX25014_IOUT2 (0x16)
+#define MAX25014_IOUT3 (0x17)
+#define MAX25014_IOUT4 (0x18)
+#define MAX25014_OPEN (0x1B)
+#define MAX25014_SHORT_GND (0x1C)
+#define MAX25014_SHORT_LED (0x1D)
+#define MAX25014_MASK (0x1E)
+#define MAX25014_DIAG (0x1F)
+
+#define MAX25014_IMODE_HDIM BIT(2)
+#define MAX25014_ISET_ENABLE BIT(5)
+#define MAX25014_ISET_PSEN BIT(4)
+#define MAX25014_DIAG_HW_RST BIT(2)
+#define MAX25014_SETTING_FPWM GENMASK(6, 4)
+
+struct max25014 {
+ struct i2c_client *client;
+ struct backlight_device *bl;
+ struct regmap *regmap;
+ struct max25014_platform_data *pdata;
+ struct gpio_desc *enable;
+ struct regulator *vin; /* regulator for boost converter Vin rail */
+ uint32_t initial_brightness;
+ uint32_t iset;
+ uint8_t strings_mask;
+};
+
+static const struct regmap_config max25014_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = MAX25014_DIAG,
+};
+
+/**
+ * @brief control the brightness with i2c registers
+ *
+ * @param regmap trivial
+ * @param brt brightness
+ * @return int
+ */
+static int max25014_register_control(struct regmap *regmap, uint32_t brt)
+{
+ uint32_t reg = TON_STEP * brt;
+ int ret;
+ /*
+ * 18 bit number lowest, 2 bits in first register,
+ * next lowest 8 in the L register, next 8 in the H register
+ * Seemingly setting the strength of only one string controls all of
+ * them, individual settings don't affect the outcome.
+ */
+
+ ret = regmap_write(regmap, MAX25014_TON_1_4_LSB, reg & 0b00000011);
+ if (ret != 0)
+ return ret;
+ ret = regmap_write(regmap, MAX25014_TON1L, (reg >> 2) & 0b11111111);
+ if (ret != 0)
+ return ret;
+ return regmap_write(regmap, MAX25014_TON1H, (reg >> 10) & 0b11111111);
+}
+
+static int max25014_check_errors(struct max25014 *maxim)
+{
+ uint8_t i;
+ int ret;
+ uint32_t val;
+
+ ret = regmap_read(maxim->regmap, MAX25014_OPEN, &val);
+ if (ret != 0)
+ return ret;
+ if (val > 0) {
+ dev_err(&maxim->client->dev, "Open led strings detected on:\n");
+ for (i = 0; i < 4; i++) {
+ if (val & 1 << i)
+ dev_err(&maxim->client->dev, "string %d\n", i + 1);
+ }
+ return -EIO;
+ }
+
+ ret = regmap_read(maxim->regmap, MAX25014_SHORT_GND, &val);
+ if (ret != 0)
+ return ret;
+ if (val > 0) {
+ dev_err(&maxim->client->dev, "Short to ground detected on:\n");
+ for (i = 0; i < 4; i++) {
+ if (val & 1 << i)
+ dev_err(&maxim->client->dev, "string %d\n", i + 1);
+ }
+ return -EIO;
+ }
+
+ ret = regmap_read(maxim->regmap, MAX25014_SHORT_GND, &val);
+ if (ret != 0)
+ return ret;
+ if (val > 0) {
+ dev_err(&maxim->client->dev, "Shorted led detected on:\n");
+ for (i = 0; i < 4; i++) {
+ if (val & 1 << i)
+ dev_err(&maxim->client->dev, "string %d\n", i + 1);
+ }
+ return -EIO;
+ }
+
+ ret = regmap_read(maxim->regmap, MAX25014_DIAG, &val);
+ if (ret != 0)
+ return ret;
+ /*
+ * The HW_RST bit always starts at 1 after power up.
+ * It is reset on first read, does not indicate an error.
+ */
+ if (val > 0 && val != MAX25014_DIAG_HW_RST) {
+ if (val & 0b1)
+ dev_err(&maxim->client->dev, "Overtemperature shutdown\n");
+ if (val & 0b10)
+ dev_warn(&maxim->client->dev,
+ "Chip is getting too hot (>125C)\n");
+ if (val & 0b1000)
+ dev_err(&maxim->client->dev, "Boost converter overvoltage\n");
+ if (val & 0b10000)
+ dev_err(&maxim->client->dev, "Boost converter undervoltage\n");
+ if (val & 0b100000)
+ dev_err(&maxim->client->dev, "IREF out of range\n");
+ return -EIO;
+ }
+ return 0;
+}
+
+/*
+ * 1. disable unused strings
+ * 2. set dim mode
+ * 3. set initial brightness
+ * 4. set setting register
+ * 5. enable the backlight
+ */
+static int max25014_configure(struct max25014 *maxim)
+{
+ int ret;
+ uint32_t val;
+
+ ret = regmap_write(maxim->regmap, MAX25014_DISABLE,
+ maxim->strings_mask);
+ if (ret != 0)
+ return ret;
+
+ ret = regmap_write(maxim->regmap, MAX25014_IMODE, MAX25014_IMODE_HDIM);
+ if (ret != 0)
+ return ret;
+
+ max25014_register_control(maxim->regmap,
+ maxim->initial_brightness);
+
+ ret = regmap_read(maxim->regmap, MAX25014_SETTING, &val);
+ if (ret != 0)
+ return ret;
+
+ ret = regmap_write(
+ maxim->regmap, MAX25014_SETTING,
+ val & ~MAX25014_SETTING_FPWM);
+ if (ret != 0)
+ return ret;
+
+ ret = regmap_write(maxim->regmap, MAX25014_ISET,
+ maxim->iset | MAX25014_ISET_ENABLE | MAX25014_ISET_PSEN);
+ return ret;
+}
+
+static int max25014_update_status(struct backlight_device *bl_dev)
+{
+ struct max25014 *maxim = bl_get_data(bl_dev);
+
+ if (bl_dev->props.state & BL_CORE_SUSPENDED)
+ bl_dev->props.brightness = 0;
+
+ return max25014_register_control(maxim->regmap, bl_dev->props.brightness);
+}
+
+static const struct backlight_ops max25014_bl_ops = {
+ .options = BL_CORE_SUSPENDRESUME,
+ .update_status = max25014_update_status,
+};
+
+static int max25014_parse_dt(struct max25014 *maxim)
+{
+ struct device *dev = &maxim->client->dev;
+ struct device_node *node = dev->of_node;
+ uint32_t strings[4];
+ int res, i;
+
+ if (!node) {
+ dev_err(dev, "no platform data\n");
+ return -EINVAL;
+ }
+
+ res = of_property_count_u32_elems(node, "maxim,strings");
+ if (res == 4) {
+ of_property_read_u32_array(node, "maxim,strings", strings, 4);
+ } else {
+ dev_err(dev, "strings property not correctly defined\n");
+ return -EINVAL;
+ }
+
+ for (i = 0; i < 4; i++) {
+ if (strings[i] == 0)
+ maxim->strings_mask |= 1 << i;
+ }
+
+ maxim->initial_brightness = 50U;
+ of_property_read_u32(node, "default-brightness", &maxim->initial_brightness);
+ maxim->iset = MAX25014_ISET_DEFAULT_100;
+ of_property_read_u32(node, "maxim,iset", &maxim->iset);
+
+ if (maxim->iset < 0 || maxim->iset > 15) {
+ dev_err(dev,
+ "Invalid iset, should be a value from 0-15, entered was %d\n",
+ maxim->iset);
+ return -EINVAL;
+ }
+
+ if (maxim->initial_brightness < 0 || maxim->initial_brightness > 100) {
+ dev_err(dev,
+ "Invalid initial brightness, should be a value from 0-100, entered was %d\n",
+ maxim->initial_brightness);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int max25014_probe(struct i2c_client *cl)
+{
+ struct backlight_device *bl;
+ const struct i2c_device_id *id = i2c_client_get_device_id(cl);
+ struct max25014 *maxim;
+ struct backlight_properties props;
+ int ret;
+
+ maxim = devm_kzalloc(&cl->dev, sizeof(struct max25014), GFP_KERNEL);
+ if (!maxim)
+ return -ENOMEM;
+
+ maxim->client = cl;
+
+ ret = max25014_parse_dt(maxim);
+ if (ret < 0)
+ return ret;
+
+ maxim->vin = devm_regulator_get(&maxim->client->dev, "power");
+ if (IS_ERR(maxim->vin)) {
+ if (PTR_ERR(maxim->vin) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+ maxim->vin = NULL;
+ }
+
+ if (maxim->vin) {
+ ret = regulator_enable(maxim->vin);
+ if (ret < 0) {
+ dev_err(&maxim->client->dev, "failed to enable Vin: %d\n", ret);
+ return ret;
+ }
+ }
+
+ maxim->enable =
+ devm_gpiod_get_optional(&maxim->client->dev, "enable", GPIOD_ASIS);
+ if (IS_ERR(maxim->enable)) {
+ ret = PTR_ERR(maxim->enable);
+ dev_err(&maxim->client->dev, "failed to get enable gpio: %d\n", ret);
+ goto disable_vin;
+ }
+
+ if (maxim->enable) {
+ gpiod_set_value_cansleep(maxim->enable, 1);
+
+ /* Datasheet Electrical Characteristics tSTARTUP 2ms */
+ usleep_range(2000, 2500);
+ }
+
+ maxim->regmap = devm_regmap_init_i2c(cl, &max25014_regmap_config);
+ if (IS_ERR(maxim->regmap)) {
+ ret = PTR_ERR(maxim->regmap);
+ dev_err(&maxim->client->dev, "failed to initialize the i2c regmap: %d\n", ret);
+ goto disable_full;
+ }
+
+ i2c_set_clientdata(cl, maxim);
+
+ ret = max25014_check_errors(maxim);
+ if (ret) { /* error is already reported in the above function */
+ goto disable_full;
+ }
+
+ ret = max25014_configure(maxim);
+ if (ret) {
+ dev_err(&maxim->client->dev, "device config err: %d", ret);
+ goto disable_full;
+ }
+
+ memset(&props, 0, sizeof(props));
+ props.type = BACKLIGHT_PLATFORM;
+ props.max_brightness = MAX_BRIGHTNESS;
+
+ props.brightness = maxim->initial_brightness;
+
+ bl = devm_backlight_device_register(&maxim->client->dev, id->name, &maxim->client->dev,
+ maxim, &max25014_bl_ops, &props);
+ if (IS_ERR(bl))
+ return PTR_ERR(bl);
+
+ maxim->bl = bl;
+
+ return 0;
+
+disable_full:
+ if (maxim->enable)
+ gpiod_set_value_cansleep(maxim->enable, 0);
+disable_vin:
+ if (maxim->vin)
+ regulator_disable(maxim->vin);
+ return ret;
+}
+
+static void max25014_remove(struct i2c_client *cl)
+{
+ struct max25014 *maxim = i2c_get_clientdata(cl);
+
+ maxim->bl->props.brightness = 0;
+ max25014_update_status(maxim->bl);
+ if (maxim->enable)
+ gpiod_set_value_cansleep(maxim->enable, 0);
+ if (maxim->vin)
+ regulator_disable(maxim->vin);
+}
+
+static const struct of_device_id max25014_dt_ids[] = {
+ { .compatible = "maxim,max25014", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, max25014_dt_ids);
+
+static const struct i2c_device_id max25014_ids[] = {
+ { "max25014" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, max25014_ids);
+
+static struct i2c_driver max25014_driver = {
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .of_match_table = of_match_ptr(max25014_dt_ids),
+ },
+ .probe = max25014_probe,
+ .remove = max25014_remove,
+ .id_table = max25014_ids,
+};
+module_i2c_driver(max25014_driver);
+
+MODULE_DESCRIPTION("Maxim MAX25014 backlight driver");
+MODULE_AUTHOR("Maud Spierings <maudspierings@gocontroll.com>");
+MODULE_LICENSE("GPL");
--
2.50.1
^ permalink raw reply related
* [PATCH v2 1/4] dt-bindings: backlight: Add max25014 bindings
From: Maud Spierings via B4 Relay @ 2025-08-19 10:58 UTC (permalink / raw)
To: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam
Cc: dri-devel, linux-leds, devicetree, linux-kernel, linux-fbdev, imx,
linux-arm-kernel, Maud Spierings
In-Reply-To: <20250819-max25014-v2-0-5fd7aeb141ea@gocontroll.com>
From: Maud Spierings <maudspierings@gocontroll.com>
The Maxim MAX25014 is a 4-channel automotive grade backlight driver IC
with intgrated boost controller.
Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>
---
.../bindings/leds/backlight/maxim,max25014.yaml | 79 ++++++++++++++++++++++
MAINTAINERS | 5 ++
2 files changed, 84 insertions(+)
diff --git a/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..30b591152fa31d5e43243cac44c72028b05b5f8a
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
@@ -0,0 +1,79 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/maxim,max25014.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Maxim max25014 backlight controller
+
+maintainers:
+ - Maud Spierings <maudspierings@gocontroll.com>
+
+allOf:
+ - $ref: common.yaml#
+
+properties:
+ compatible:
+ enum:
+ - maxim,max25014
+
+ reg:
+ maxItems: 1
+
+ enable-gpios:
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ power-supply:
+ description: Regulator which controls the boost converter input rail.
+
+ pwms:
+ maxItems: 1
+
+ maxim,iset:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ default: 11
+ description:
+ Value of the ISET register field (0-15).
+
+ maxim,strings:
+ $ref: /schemas/types.yaml#/definitions/uint32-array
+ description:
+ A 4-bit bitfield that describes which led strings to turn on.
+ minItems: 4
+ maxItems: 4
+
+required:
+ - compatible
+ - reg
+ - maxim,strings
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ #include <dt-bindings/interrupt-controller/irq.h>
+
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ backlight: backlight@6f {
+ reg = <0x6f>;
+ compatible = "maxim,max25014";
+ default-brightness = <50>;
+ enable-gpios = <&gpio1 4 GPIO_ACTIVE_HIGH>;
+ interrupt-parent = <&gpio1>;
+ interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_backlight>;
+ power-supply = <®_backlight>;
+ pwms = <&pwm1>;
+ maxim,iset = <7>;
+ maxim,strings = <1 1 1 1>;
+ };
+ };
+
diff --git a/MAINTAINERS b/MAINTAINERS
index e81d5f9fbd16cc384356804390d65652bbb9e3f6..11c73d2e37fac22aea852152746236c1472f41b8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14972,6 +14972,11 @@ F: Documentation/userspace-api/media/drivers/max2175.rst
F: drivers/media/i2c/max2175*
F: include/uapi/linux/max2175.h
+MAX25014 BACKLIGHT DRIVER
+M: Maud Spierings <maudspierings@gocontroll.com>
+S: Maintained
+F: Documentation/devicetree/bindings/leds/backlight/maxim,max25014.yaml
+
MAX31335 RTC DRIVER
M: Antoniu Miclaus <antoniu.miclaus@analog.com>
L: linux-rtc@vger.kernel.org
--
2.50.1
^ permalink raw reply related
* [PATCH v2 0/4] backlight: add new max25014 backlight driver
From: Maud Spierings via B4 Relay @ 2025-08-19 10:58 UTC (permalink / raw)
To: Lee Jones, Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam
Cc: dri-devel, linux-leds, devicetree, linux-kernel, linux-fbdev, imx,
linux-arm-kernel, Maud Spierings,
"Maud Spierings maudspierings"
The Maxim MAX25014 is an automotive grade backlight driver IC. Its
datasheet can be found at [1].
With its integrated boost controller, it can power 4 channels (led
strings) and has a number of different modes using pwm and or i2c.
Currently implemented is only i2c control.
link: https://www.analog.com/media/en/technical-documentation/data-sheets/MAX25014.pdf [1]
Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>
---
Changes in v2:
- Remove leftover unused property from the bindings example
- Complete the bindings example with all properties
- Remove some double info from the maxim,iset property
- Remove platform_data header, fold its data into the max25014 struct
- Don't force defines to be unsigned
- Remove stray struct max25014 declaration
- Remove chipname and device from the max25014 struct
- Inline the max25014_backlight_register() and strings_mask() functions
- Remove CONFIG_OF ifdef
- Link to v1: https://lore.kernel.org/r/20250725-max25014-v1-0-0e8cce92078e@gocontroll.com
---
Maud Spierings (4):
dt-bindings: backlight: Add max25014 bindings
backlight: add max25014atg backlight
arm64: dts: freescale: moduline-display-av101hdt-a10: add backlight
arm64: dts: freescale: moduline-display-av123z7m-n17: add backlight
.../bindings/leds/backlight/maxim,max25014.yaml | 79 +++++
MAINTAINERS | 6 +
...x8p-ml81-moduline-display-106-av101hdt-a10.dtso | 21 ++
...x8p-ml81-moduline-display-106-av123z7m-n17.dtso | 19 +-
drivers/video/backlight/Kconfig | 7 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/max25014.c | 395 +++++++++++++++++++++
7 files changed, 527 insertions(+), 1 deletion(-)
---
base-commit: 886e5e7b0432360842303d587bb4a65d10741ae8
change-id: 20250626-max25014-4207591e1af5
Best regards,
--
Maud Spierings <maudspierings@gocontroll.com>
^ permalink raw reply
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