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* [PATCH] fbdev: sh_mobile_lcdcfb: Restore the per-overlay sysfs attributes
@ 2026-09-07  2:18 Karl Mehltretter
  2026-09-10 21:15 ` Helge Deller
  0 siblings, 1 reply; 3+ messages in thread
From: Karl Mehltretter @ 2026-09-07  2:18 UTC (permalink / raw)
  To: Helge Deller
  Cc: Karl Mehltretter, Shixiong Ou, Chintan Patel, Laurent Pinchart,
	Thomas Zimmermann, linux-fbdev, dri-devel, stable

The ovl_* files documented in
Documentation/ABI/testing/sysfs-devices-platform-sh_mobile_lcdc_fb no
longer exist.

Commit a979182a2453 ("fbdev: lcdcfb: Register sysfs groups through driver
core") moved the attributes from each overlay's framebuffer device to
the platform driver's dev_groups and renamed them overlay_*. There is
now only one set of attributes for the whole LCDC. The callbacks still
expect dev_get_drvdata() to return a struct fb_info, but the platform
device holds struct sh_mobile_lcdc_priv, so they access the wrong
structure.

Restore the documented names and register the group on each overlay's
framebuffer device with device_add_groups(). Remove it with
device_remove_groups() before unregistering the framebuffer. Skip
creation when info->dev is NULL, as the old device_create_file() calls did.

Drop the CONFIG_FB_DEVICE guard, since the driver already depends on it.

Fixes: a979182a2453 ("fbdev: lcdcfb: Register sysfs groups through driver core")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
---
Found while reviewing the sysfs ABI documentation.

Compile-tested only (allmodconfig, W=1), I have no SH-Mobile hardware.

 drivers/video/fbdev/sh_mobile_lcdcfb.c | 37 +++++++++++++++++---------
 1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/drivers/video/fbdev/sh_mobile_lcdcfb.c b/drivers/video/fbdev/sh_mobile_lcdcfb.c
index e8324b01700f..18fc4e465283 100644
--- a/drivers/video/fbdev/sh_mobile_lcdcfb.c
+++ b/drivers/video/fbdev/sh_mobile_lcdcfb.c
@@ -1337,22 +1337,24 @@ overlay_rop3_store(struct device *dev, struct device_attribute *attr,
 	return count;
 }
 
-static DEVICE_ATTR_RW(overlay_alpha);
-static DEVICE_ATTR_RW(overlay_mode);
-static DEVICE_ATTR_RW(overlay_position);
-static DEVICE_ATTR_RW(overlay_rop3);
-
-static struct attribute *overlay_sysfs_attrs[] __maybe_unused = {
-	&dev_attr_overlay_alpha.attr,
-	&dev_attr_overlay_mode.attr,
-	&dev_attr_overlay_position.attr,
-	&dev_attr_overlay_rop3.attr,
+static struct device_attribute dev_attr_ovl_alpha =
+	__ATTR(ovl_alpha, 0644, overlay_alpha_show, overlay_alpha_store);
+static struct device_attribute dev_attr_ovl_mode =
+	__ATTR(ovl_mode, 0644, overlay_mode_show, overlay_mode_store);
+static struct device_attribute dev_attr_ovl_position =
+	__ATTR(ovl_position, 0644, overlay_position_show, overlay_position_store);
+static struct device_attribute dev_attr_ovl_rop3 =
+	__ATTR(ovl_rop3, 0644, overlay_rop3_show, overlay_rop3_store);
+
+static struct attribute *overlay_sysfs_attrs[] = {
+	&dev_attr_ovl_alpha.attr,
+	&dev_attr_ovl_mode.attr,
+	&dev_attr_ovl_position.attr,
+	&dev_attr_ovl_rop3.attr,
 	NULL,
 };
 
-#ifdef CONFIG_FB_DEVICE
 ATTRIBUTE_GROUPS(overlay_sysfs);
-#endif
 
 static const struct fb_fix_screeninfo sh_mobile_lcdc_overlay_fix  = {
 	.id =		"SH Mobile LCDC",
@@ -1513,6 +1515,7 @@ sh_mobile_lcdc_overlay_fb_unregister(struct sh_mobile_lcdc_overlay *ovl)
 	if (info == NULL || info->dev == NULL)
 		return;
 
+	device_remove_groups(info->dev, overlay_sysfs_groups);
 	unregister_framebuffer(ovl->info);
 }
 
@@ -1530,6 +1533,15 @@ sh_mobile_lcdc_overlay_fb_register(struct sh_mobile_lcdc_overlay *ovl)
 	if (ret < 0)
 		return ret;
 
+	/* The framebuffer device is optional, see fb_device_create(). */
+	if (info->dev) {
+		ret = device_add_groups(info->dev, overlay_sysfs_groups);
+		if (ret < 0) {
+			unregister_framebuffer(info);
+			return ret;
+		}
+	}
+
 	dev_info(lcdc->dev, "registered %s/overlay %u as %dx%d %dbpp.\n",
 		 dev_name(lcdc->dev), ovl->index, info->var.xres,
 		 info->var.yres, info->var.bits_per_pixel);
@@ -2637,7 +2649,6 @@ static int sh_mobile_lcdc_probe(struct platform_device *pdev)
 static struct platform_driver sh_mobile_lcdc_driver = {
 	.driver		= {
 		.name		= "sh_mobile_lcdc_fb",
-		.dev_groups	= overlay_sysfs_groups,
 		.pm		= &sh_mobile_lcdc_dev_pm_ops,
 	},
 	.probe		= sh_mobile_lcdc_probe,

base-commit: 986c24e0fe44f844b44d365b71ce831947f50298
-- 
2.53.0

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] fbdev: sh_mobile_lcdcfb: Restore the per-overlay sysfs attributes
  2026-09-07  2:18 [PATCH] fbdev: sh_mobile_lcdcfb: Restore the per-overlay sysfs attributes Karl Mehltretter
@ 2026-09-10 21:15 ` Helge Deller
  2026-09-11  1:41   ` Shixiong Ou
  0 siblings, 1 reply; 3+ messages in thread
From: Helge Deller @ 2026-09-10 21:15 UTC (permalink / raw)
  To: Karl Mehltretter
  Cc: Shixiong Ou, Chintan Patel, Laurent Pinchart, Thomas Zimmermann,
	linux-fbdev, dri-devel, stable, Arnd Bergmann

On 9/7/26 04:18, Karl Mehltretter wrote:
> The ovl_* files documented in
> Documentation/ABI/testing/sysfs-devices-platform-sh_mobile_lcdc_fb no
> longer exist.
> 
> Commit a979182a2453 ("fbdev: lcdcfb: Register sysfs groups through driver
> core") moved the attributes from each overlay's framebuffer device to
> the platform driver's dev_groups and renamed them overlay_*. There is
> now only one set of attributes for the whole LCDC. The callbacks still
> expect dev_get_drvdata() to return a struct fb_info, but the platform
> device holds struct sh_mobile_lcdc_priv, so they access the wrong
> structure.
> 
> Restore the documented names and register the group on each overlay's
> framebuffer device with device_add_groups(). Remove it with
> device_remove_groups() before unregistering the framebuffer. Skip
> creation when info->dev is NULL, as the old device_create_file() calls did.
> 
> Drop the CONFIG_FB_DEVICE guard, since the driver already depends on it.
> 
> Fixes: a979182a2453 ("fbdev: lcdcfb: Register sysfs groups through driver core")
> Cc: stable@vger.kernel.org
> Assisted-by: LLM
> Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
> ---
> Found while reviewing the sysfs ABI documentation.
> 
> Compile-tested only (allmodconfig, W=1), I have no SH-Mobile hardware.


This all seems correct, but since it reverts a few of the last patches
I'd prefer that some other person could also review it....

  
>   drivers/video/fbdev/sh_mobile_lcdcfb.c | 37 +++++++++++++++++---------
>   1 file changed, 24 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/video/fbdev/sh_mobile_lcdcfb.c b/drivers/video/fbdev/sh_mobile_lcdcfb.c
> index e8324b01700f..18fc4e465283 100644
> --- a/drivers/video/fbdev/sh_mobile_lcdcfb.c
> +++ b/drivers/video/fbdev/sh_mobile_lcdcfb.c
> @@ -1337,22 +1337,24 @@ overlay_rop3_store(struct device *dev, struct device_attribute *attr,
>   	return count;
>   }
>   
> -static DEVICE_ATTR_RW(overlay_alpha);
> -static DEVICE_ATTR_RW(overlay_mode);
> -static DEVICE_ATTR_RW(overlay_position);
> -static DEVICE_ATTR_RW(overlay_rop3);
> -
> -static struct attribute *overlay_sysfs_attrs[] __maybe_unused = {
> -	&dev_attr_overlay_alpha.attr,
> -	&dev_attr_overlay_mode.attr,
> -	&dev_attr_overlay_position.attr,
> -	&dev_attr_overlay_rop3.attr,
> +static struct device_attribute dev_attr_ovl_alpha =
> +	__ATTR(ovl_alpha, 0644, overlay_alpha_show, overlay_alpha_store);
> +static struct device_attribute dev_attr_ovl_mode =
> +	__ATTR(ovl_mode, 0644, overlay_mode_show, overlay_mode_store);
> +static struct device_attribute dev_attr_ovl_position =
> +	__ATTR(ovl_position, 0644, overlay_position_show, overlay_position_store);
> +static struct device_attribute dev_attr_ovl_rop3 =
> +	__ATTR(ovl_rop3, 0644, overlay_rop3_show, overlay_rop3_store);
> +
> +static struct attribute *overlay_sysfs_attrs[] = {
> +	&dev_attr_ovl_alpha.attr,
> +	&dev_attr_ovl_mode.attr,
> +	&dev_attr_ovl_position.attr,
> +	&dev_attr_ovl_rop3.attr,
>   	NULL,
>   };
>   
> -#ifdef CONFIG_FB_DEVICE
>   ATTRIBUTE_GROUPS(overlay_sysfs);
> -#endif
>   
>   static const struct fb_fix_screeninfo sh_mobile_lcdc_overlay_fix  = {
>   	.id =		"SH Mobile LCDC",
> @@ -1513,6 +1515,7 @@ sh_mobile_lcdc_overlay_fb_unregister(struct sh_mobile_lcdc_overlay *ovl)
>   	if (info == NULL || info->dev == NULL)
>   		return;
>   
> +	device_remove_groups(info->dev, overlay_sysfs_groups);
>   	unregister_framebuffer(ovl->info);
>   }
>   
> @@ -1530,6 +1533,15 @@ sh_mobile_lcdc_overlay_fb_register(struct sh_mobile_lcdc_overlay *ovl)
>   	if (ret < 0)
>   		return ret;
>   
> +	/* The framebuffer device is optional, see fb_device_create(). */
> +	if (info->dev) {

I think this needs to be:
	if (dev_of_fbinfo(info)) {
to avoid compile error when CONFIG_FB_DEVICE=n.


> +		ret = device_add_groups(info->dev, overlay_sysfs_groups);

same here. dev_of_fbinfo(info).

> +		if (ret < 0) {
> +			unregister_framebuffer(info);
> +			return ret;
> +		}
> +	}
> +
>   	dev_info(lcdc->dev, "registered %s/overlay %u as %dx%d %dbpp.\n",
>   		 dev_name(lcdc->dev), ovl->index, info->var.xres,
>   		 info->var.yres, info->var.bits_per_pixel);
> @@ -2637,7 +2649,6 @@ static int sh_mobile_lcdc_probe(struct platform_device *pdev)
>   static struct platform_driver sh_mobile_lcdc_driver = {
>   	.driver		= {
>   		.name		= "sh_mobile_lcdc_fb",
> -		.dev_groups	= overlay_sysfs_groups,
>   		.pm		= &sh_mobile_lcdc_dev_pm_ops,
>   	},
>   	.probe		= sh_mobile_lcdc_probe,
> 
> base-commit: 986c24e0fe44f844b44d365b71ce831947f50298


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] fbdev: sh_mobile_lcdcfb: Restore the per-overlay sysfs attributes
  2026-09-10 21:15 ` Helge Deller
@ 2026-09-11  1:41   ` Shixiong Ou
  0 siblings, 0 replies; 3+ messages in thread
From: Shixiong Ou @ 2026-09-11  1:41 UTC (permalink / raw)
  To: Helge Deller, Karl Mehltretter
  Cc: Chintan Patel, Laurent Pinchart, Thomas Zimmermann, linux-fbdev,
	dri-devel, stable, Arnd Bergmann


On 2026/9/11 05:15, Helge Deller wrote:
> On 9/7/26 04:18, Karl Mehltretter wrote:
>> The ovl_* files documented in
>> Documentation/ABI/testing/sysfs-devices-platform-sh_mobile_lcdc_fb no
>> longer exist.
>>
>> Commit a979182a2453 ("fbdev: lcdcfb: Register sysfs groups through 
>> driver
>> core") moved the attributes from each overlay's framebuffer device to
>> the platform driver's dev_groups and renamed them overlay_*. There is
>> now only one set of attributes for the whole LCDC. The callbacks still
>> expect dev_get_drvdata() to return a struct fb_info, but the platform
>> device holds struct sh_mobile_lcdc_priv, so they access the wrong
>> structure.
>>
>> Restore the documented names and register the group on each overlay's
>> framebuffer device with device_add_groups(). Remove it with
>> device_remove_groups() before unregistering the framebuffer. Skip
>> creation when info->dev is NULL, as the old device_create_file() 
>> calls did.
>>
>> Drop the CONFIG_FB_DEVICE guard, since the driver already depends on it.
>>
>> Fixes: a979182a2453 ("fbdev: lcdcfb: Register sysfs groups through 
>> driver core")
>> Cc: stable@vger.kernel.org
>> Assisted-by: LLM
>> Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
>> ---
>> Found while reviewing the sysfs ABI documentation.
>>
>> Compile-tested only (allmodconfig, W=1), I have no SH-Mobile hardware.
>
>
> This all seems correct, but since it reverts a few of the last patches
> I'd prefer that some other person could also review it....
>
Looks good to me, and I agree .dev_groups is wrong here.

Shixiong.

>
>>   drivers/video/fbdev/sh_mobile_lcdcfb.c | 37 +++++++++++++++++---------
>>   1 file changed, 24 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/video/fbdev/sh_mobile_lcdcfb.c 
>> b/drivers/video/fbdev/sh_mobile_lcdcfb.c
>> index e8324b01700f..18fc4e465283 100644
>> --- a/drivers/video/fbdev/sh_mobile_lcdcfb.c
>> +++ b/drivers/video/fbdev/sh_mobile_lcdcfb.c
>> @@ -1337,22 +1337,24 @@ overlay_rop3_store(struct device *dev, struct 
>> device_attribute *attr,
>>       return count;
>>   }
>>   -static DEVICE_ATTR_RW(overlay_alpha);
>> -static DEVICE_ATTR_RW(overlay_mode);
>> -static DEVICE_ATTR_RW(overlay_position);
>> -static DEVICE_ATTR_RW(overlay_rop3);
>> -
>> -static struct attribute *overlay_sysfs_attrs[] __maybe_unused = {
>> -    &dev_attr_overlay_alpha.attr,
>> -    &dev_attr_overlay_mode.attr,
>> -    &dev_attr_overlay_position.attr,
>> -    &dev_attr_overlay_rop3.attr,
>> +static struct device_attribute dev_attr_ovl_alpha =
>> +    __ATTR(ovl_alpha, 0644, overlay_alpha_show, overlay_alpha_store);
>> +static struct device_attribute dev_attr_ovl_mode =
>> +    __ATTR(ovl_mode, 0644, overlay_mode_show, overlay_mode_store);
>> +static struct device_attribute dev_attr_ovl_position =
>> +    __ATTR(ovl_position, 0644, overlay_position_show, 
>> overlay_position_store);
>> +static struct device_attribute dev_attr_ovl_rop3 =
>> +    __ATTR(ovl_rop3, 0644, overlay_rop3_show, overlay_rop3_store);
>> +
>> +static struct attribute *overlay_sysfs_attrs[] = {
>> +    &dev_attr_ovl_alpha.attr,
>> +    &dev_attr_ovl_mode.attr,
>> +    &dev_attr_ovl_position.attr,
>> +    &dev_attr_ovl_rop3.attr,
>>       NULL,
>>   };
>>   -#ifdef CONFIG_FB_DEVICE
>>   ATTRIBUTE_GROUPS(overlay_sysfs);
>> -#endif
>>     static const struct fb_fix_screeninfo sh_mobile_lcdc_overlay_fix  
>> = {
>>       .id =        "SH Mobile LCDC",
>> @@ -1513,6 +1515,7 @@ sh_mobile_lcdc_overlay_fb_unregister(struct 
>> sh_mobile_lcdc_overlay *ovl)
>>       if (info == NULL || info->dev == NULL)
>>           return;
>>   +    device_remove_groups(info->dev, overlay_sysfs_groups);
>>       unregister_framebuffer(ovl->info);
>>   }
>>   @@ -1530,6 +1533,15 @@ sh_mobile_lcdc_overlay_fb_register(struct 
>> sh_mobile_lcdc_overlay *ovl)
>>       if (ret < 0)
>>           return ret;
>>   +    /* The framebuffer device is optional, see fb_device_create(). */
>> +    if (info->dev) {
>
> I think this needs to be:
>     if (dev_of_fbinfo(info)) {
> to avoid compile error when CONFIG_FB_DEVICE=n.
>
>
>> +        ret = device_add_groups(info->dev, overlay_sysfs_groups);
>
> same here. dev_of_fbinfo(info).
>
>> +        if (ret < 0) {
>> +            unregister_framebuffer(info);
>> +            return ret;
>> +        }
>> +    }
>> +
>>       dev_info(lcdc->dev, "registered %s/overlay %u as %dx%d %dbpp.\n",
>>            dev_name(lcdc->dev), ovl->index, info->var.xres,
>>            info->var.yres, info->var.bits_per_pixel);
>> @@ -2637,7 +2649,6 @@ static int sh_mobile_lcdc_probe(struct 
>> platform_device *pdev)
>>   static struct platform_driver sh_mobile_lcdc_driver = {
>>       .driver        = {
>>           .name        = "sh_mobile_lcdc_fb",
>> -        .dev_groups    = overlay_sysfs_groups,
>>           .pm        = &sh_mobile_lcdc_dev_pm_ops,
>>       },
>>       .probe        = sh_mobile_lcdc_probe,
>>
>> base-commit: 986c24e0fe44f844b44d365b71ce831947f50298

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2026-09-11  1:41 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2026-09-07  2:18 [PATCH] fbdev: sh_mobile_lcdcfb: Restore the per-overlay sysfs attributes Karl Mehltretter
2026-09-10 21:15 ` Helge Deller
2026-09-11  1:41   ` Shixiong Ou

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