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authorThomas Zimmermann <tzimmermann@suse.de>2023-02-16 17:06:20 +0300
committerThomas Zimmermann <tzimmermann@suse.de>2023-02-21 15:26:18 +0300
commit3fb1f62f80a1d249260db5ea9e22c51e52fab9ae (patch)
tree55e0969d0ec4048a2a937187516e9476500b130d /drivers/gpu/drm/drm_fb_helper.c
parentfb073aa27a7e1b8c968c05c5447a77d49e832ec5 (diff)
downloadlinux-3fb1f62f80a1d249260db5ea9e22c51e52fab9ae.tar.xz
drm/fb-helper: Remove drm_fb_helper_unprepare() from drm_fb_helper_fini()
Move drm_fb_helper_unprepare() from drm_fb_helper_fini() into the calling fbdev implementation. Avoids a possible stale mutex with generic fbdev code. As indicated by its name, drm_fb_helper_prepare() prepares struct drm_fb_helper before setting up the fbdev support with a call to drm_fb_helper_init(). In legacy fbdev emulation, this happens next to each other. If successful, drm_fb_helper_fini() later tear down the fbdev device and also unprepare via drm_fb_helper_unprepare(). Generic fbdev emulation prepares struct drm_fb_helper immediately after allocating the instance. It only calls drm_fb_helper_init() as part of processing a hotplug event. If the hotplug-handling fails, it runs drm_fb_helper_fini(). This unprepares the fb-helper instance and the next hotplug event runs on stale data. Solve this by moving drm_fb_helper_unprepare() from drm_fb_helper_fini() into the fbdev implementations. Call it right before freeing the fb-helper instance. Fixes: 643231b28380 ("drm/fbdev-generic: Minimize hotplug error handling") Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Javier Martinez Canillas <javierm@redhat.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: dri-devel@lists.freedesktop.org Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20230216140620.17699-1-tzimmermann@suse.de
Diffstat (limited to 'drivers/gpu/drm/drm_fb_helper.c')
-rw-r--r--drivers/gpu/drm/drm_fb_helper.c2
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 28c428e9c530..a39998047f8a 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -590,8 +590,6 @@ void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
}
mutex_unlock(&kernel_fb_helper_lock);
- drm_fb_helper_unprepare(fb_helper);
-
if (!fb_helper->client.funcs)
drm_client_release(&fb_helper->client);
}