On Wed, Apr 13, 2022 at 12:50:50PM +0200, Javier Martinez Canillas wrote: > On 4/13/22 11:24, Thomas Zimmermann wrote: > > A workaround makes fbdev hot-unplugging work for framebuffers without > > device. The only user for this feature was offb. As each OF framebuffer > > now has an associated platform device, the workaround is no longer > > needed. Remove it. Effectively reverts commit 0f525289ff0d ("fbdev: Fix > > unregistering of framebuffers without device"). > > > > Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> > > --- > > drivers/video/fbdev/core/fbmem.c | 9 +-------- > > 1 file changed, 1 insertion(+), 8 deletions(-) > > > > diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c > > index bc6ed750e915..bdd00d381bbc 100644 > > --- a/drivers/video/fbdev/core/fbmem.c > > +++ b/drivers/video/fbdev/core/fbmem.c > > @@ -1579,14 +1579,7 @@ static void do_remove_conflicting_framebuffers(struct apertures_struct *a, > > * If it's not a platform device, at least print a warning. A > > * fix would add code to remove the device from the system. > > */ > > - if (!device) { > > - /* TODO: Represent each OF framebuffer as its own > > - * device in the device hierarchy. For now, offb > > - * doesn't have such a device, so unregister the > > - * framebuffer as before without warning. > > - */ > > - do_unregister_framebuffer(registered_fb[i]); > > Maybe we could still keep this for a couple of releases but with a big > warning that's not supported in case there are out-of-tree drivers out > there that still do this ? > > Or at least a warning if the do_unregister_framebuffer() call is removed. Yeah dying while holding console_lock isn't fun, and not having a WARN_ON + bail-out code pretty much forces bug reporters to do a bisect here to give us something more than "machine dies at boot with no messages". I'd just outright keep the WARN_ON here for 1-2 years even to really make sure we got all the bug reports, since often these older machines only update onto LTS releases. And it needs to be a WARN_ON + bail out since BUG_ON is as bad as just oopsing. -Daniel > > Regardless of what you chose to do, the patch looks good to me. > > Reviewed-by: Javier Martinez Canillas <javierm@xxxxxxxxxx> > > -- > Best regards, > > Javier Martinez Canillas > Linux Engineering > Red Hat > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch