This is a note to let you know that I've just added the patch titled
Revert "drm/fb-helper: improve DRM fbdev emulation device names"
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
revert-drm-fb-helper-improve-drm-fbdev-emulation-dev.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9dd5c04d5d18339044fc4475fa87fbd71a99ebc2
Author: Javier Martinez Canillas <javierm@xxxxxxxxxx>
Date: Wed Oct 20 18:57:40 2021 +0200
Revert "drm/fb-helper: improve DRM fbdev emulation device names"
[ Upstream commit 842470c4e211f284a224842849b1fa81b130c154 ]
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 <js@xxxxxxxxx>
Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20211020165740.3011927-1-javierm@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 8e7a124d6c5a3..22bf690910b25 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);
}
