On Wed, Jun 15, 2011 at 1:58 PM, Bruno Prémont <bonbons@xxxxxxxxxxxxxxxxx> wrote: > > Hi, > > On Wed, 15 Jun 2011 09:09:24 Wanlong Gao <wanlong.gao@xxxxxxxxx> wrote: > > <snip> > > Hi Francis: > > can you test this patch? > > Do you have a deadlock trace which you are trying to fix? No, I just look at the code and try to fix this but I'm not sure. Can you teach me how to have a deadlock trace here? Thanks > > It's either the caller of unregister_framebuffer() which must be > changed to not call unregister_framebuffer with info's lock held or > the code reacting on the notification that must not try to acquire the > lock again. > > The interesting par is if console semaphore has some relation to this > deadlock as the order for taking both varies... It could be > lock_fb_info(); console_lock() versus console_lock(); lock_fb_info() > I see, thanks > Bruno > > > > Thanks > > ><snip> > > Not a good idea to stop taking fb_lock here. > Pretty all calls of fb_notifier_call_chain are protected by info's > lock, except the one for FB_EVENT_FB_UNREGISTERED a few lines further. Yup, thanks > > IMHO it wou make sense to add the lock around that last one so all > notifier chain calls are handled the same. > > <snip> > -- Best regards Wanlong Gao -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
