lkml.org 
[lkml]   [2022]   [May]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v5 3/7] fbdev: Restart conflicting fb removal loop when unregistering devices
From
On 5/11/22 13:30, Javier Martinez Canillas wrote:
> Drivers that want to remove registered conflicting framebuffers prior to
> register their own framebuffer, calls remove_conflicting_framebuffers().
>
> This function takes the registration_lock mutex, to prevent a races when
> drivers register framebuffer devices. But if a conflicting framebuffer
> device is found, the underlaying platform device is unregistered and this
> will lead to the platform driver .remove callback to be called, which in
> turn will call to the unregister_framebuffer() that takes the same lock.
>
> To prevent this, a struct fb_info.forced_out field was used as indication
> to unregister_framebuffer() whether the mutex has to be grabbed or not.
>
> A cleaner solution is to drop the lock before platform_device_unregister()
> so unregister_framebuffer() can take it when called from the fbdev driver,
> and just grab the lock again after the device has been registered and do
> a removal loop restart.
>
> Since the framebuffer devices will already be removed, the loop would just
> finish when no more conflicting framebuffers are found.
>
> Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> ---
Pushed this to drm-misc (drm-misc-next). Thanks all!

--
Best regards,

Javier Martinez Canillas
Linux Engineering
Red Hat

\
 
 \ /
  Last update: 2022-05-13 14:29    [W:0.152 / U:0.680 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site