Re: Possible deadlock in videobuf_dma_init_user

[Arjan van de Ven]

On Sun, 2006-08-20 at 21:19 +0200, Petr Vandrovec wrote:
> Hello,
>   my kernel is a bit unhappy with lock ordering between mm->mmap_sem 
> and videobuf_queue->lock.
> 					Thanks,
> 						Petr Vandrovec


looks like a real deadlock to me...

bttv_prepare_buffer takes mutex then
videobuf_dma_init_user takes mmap_sem



do_mmap_pgoff takes mmap_sem then calls
bttv_mmap which calls
videobuf_mmap_mapper takes the mutex


so a classic AB-BA deadlock....


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/