Messages in this thread | | | Date | Wed, 17 Nov 2010 15:16:27 +0800 | From | "Figo.zhang" <> | Subject | Re: [PATCH 1/1] videobuf: Initialize lists in videobuf_buffer. |
| |
On 11/17/2010 03:11 PM, Hans Verkuil wrote: > On Wednesday, November 17, 2010 02:38:09 Andrew Chew wrote: >>>> diff --git a/drivers/media/video/videobuf-dma-contig.c >>> b/drivers/media/video/videobuf-dma-contig.c >>>> index c969111..f7e0f86 100644 >>>> --- a/drivers/media/video/videobuf-dma-contig.c >>>> +++ b/drivers/media/video/videobuf-dma-contig.c >>>> @@ -193,6 +193,8 @@ static struct videobuf_buffer >>> *__videobuf_alloc_vb(size_t size) >>>> if (vb) { >>>> mem = vb->priv = ((char *)vb) + size; >>>> mem->magic = MAGIC_DC_MEM; >>>> + INIT_LIST_HEAD(&vb->stream); >>>> + INIT_LIST_HEAD(&vb->queue); >>> >>> i think it no need to be init, it just a list-entry. >> >> Okay, if that's really the case, then sh_mobile_ceu_camera.c, pxa_camera.c, mx1_camera.c, mx2_camera.c, and omap1_camera.c needs to be fixed to remove that WARN_ON(!list_empty(&vb->queue)); in their videobuf_prepare() methods, because those WARN_ON's are assuming that vb->queue is properly initialized as a list head. >> >> Which will it be? >> > > These list entries need to be inited. It is bad form to have uninitialized > list entries. It is not as if this is a big deal to initialize them properly.
in kernel source code, list entry are not often to be inited.
for example, see mm/vmscan.c register_shrinker(), no one init the shrinker->list.
another example: see mm/swapfile.c add_swap_extent(), no one init the new_se->list.
| |