This reverts commit b3484d2b03e4c940a9598aa841a52d69729c582a.
That change attempted to improve the DRM drivers fbdev emulation device
names to avoid having confusing names like "simpledrmdrmfb" in /proc/fb.
But unfortunately, there are user-space programs such as pm-utils that
match against the fbdev names and so broke after the mentioned commit.
Since the names in /proc/fb are used by tools that consider it an uAPI,
let's restore the old names even when this lead to silly names like the
one mentioned above.
Fixes: b3484d2b03e4 ("drm/fb-helper: improve DRM fbdev emulation device names")
Reported-by: Johannes Stezenbach <[email protected]>
Signed-off-by: Javier Martinez Canillas <[email protected]>
Reviewed-by: Ville Syrjälä <[email protected]>
---
Changes in v2:
- Add a comment explaining that the current /proc/fb names are an uAPI.
- Add a Fixes: tag so it can be cherry-picked by stable kernels.
- Add Ville Syrjälä's Reviewed-by tag.
drivers/gpu/drm/drm_fb_helper.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 8e7a124d6c5a..22bf690910b2 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1743,7 +1743,13 @@ void drm_fb_helper_fill_info(struct fb_info *info,
sizes->fb_width, sizes->fb_height);
info->par = fb_helper;
- snprintf(info->fix.id, sizeof(info->fix.id), "%s",
+ /*
+ * The DRM drivers fbdev emulation device name can be confusing if the
+ * driver name also has a "drm" suffix on it. Leading to names such as
+ * "simpledrmdrmfb" in /proc/fb. Unfortunately, it's an uAPI and can't
+ * be changed due user-space tools (e.g: pm-utils) matching against it.
+ */
+ snprintf(info->fix.id, sizeof(info->fix.id), "%sdrmfb",
fb_helper->dev->driver->name);
}
--
2.31.1
Hi,
On Wed, Oct 20, 2021 at 06:57:40PM +0200, Javier Martinez Canillas wrote:
> This reverts commit b3484d2b03e4c940a9598aa841a52d69729c582a.
>
> That change attempted to improve the DRM drivers fbdev emulation device
> names to avoid having confusing names like "simpledrmdrmfb" in /proc/fb.
>
> But unfortunately, there are user-space programs such as pm-utils that
> match against the fbdev names and so broke after the mentioned commit.
>
> Since the names in /proc/fb are used by tools that consider it an uAPI,
> let's restore the old names even when this lead to silly names like the
> one mentioned above.
I would like to ask about the fate of this patch. It doesn't
seem to have been picked up by anyone, does it?
Thanks,
Johannes
> Fixes: b3484d2b03e4 ("drm/fb-helper: improve DRM fbdev emulation device names")
> Reported-by: Johannes Stezenbach <[email protected]>
> Signed-off-by: Javier Martinez Canillas <[email protected]>
> Reviewed-by: Ville Syrj?l? <[email protected]>
> ---
>
> Changes in v2:
> - Add a comment explaining that the current /proc/fb names are an uAPI.
> - Add a Fixes: tag so it can be cherry-picked by stable kernels.
> - Add Ville Syrj?l?'s Reviewed-by tag.
>
> drivers/gpu/drm/drm_fb_helper.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 8e7a124d6c5a..22bf690910b2 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -1743,7 +1743,13 @@ void drm_fb_helper_fill_info(struct fb_info *info,
> sizes->fb_width, sizes->fb_height);
>
> info->par = fb_helper;
> - snprintf(info->fix.id, sizeof(info->fix.id), "%s",
> + /*
> + * The DRM drivers fbdev emulation device name can be confusing if the
> + * driver name also has a "drm" suffix on it. Leading to names such as
> + * "simpledrmdrmfb" in /proc/fb. Unfortunately, it's an uAPI and can't
> + * be changed due user-space tools (e.g: pm-utils) matching against it.
> + */
> + snprintf(info->fix.id, sizeof(info->fix.id), "%sdrmfb",
> fb_helper->dev->driver->name);
>
> }
> --
> 2.31.1
>
>
Hello Johannes,
Sorry for the late response. I was on holidays for a week and just came back.
On 12/4/21 13:41, Johannes Stezenbach wrote:
> Hi,
>
> On Wed, Oct 20, 2021 at 06:57:40PM +0200, Javier Martinez Canillas wrote:
>> This reverts commit b3484d2b03e4c940a9598aa841a52d69729c582a.
>>
>> That change attempted to improve the DRM drivers fbdev emulation device
>> names to avoid having confusing names like "simpledrmdrmfb" in /proc/fb.
>>
>> But unfortunately, there are user-space programs such as pm-utils that
>> match against the fbdev names and so broke after the mentioned commit.
>>
>> Since the names in /proc/fb are used by tools that consider it an uAPI,
>> let's restore the old names even when this lead to silly names like the
>> one mentioned above.
>
> I would like to ask about the fate of this patch. It doesn't
> seem to have been picked up by anyone, does it?
>
Thanks for the reminder. I've just pushed this to the drm-misc-fixes branch.
>
> Thanks,
> Johannes
>
Best regards,
--
Javier Martinez Canillas
Linux Engineering
Red Hat