On Fri, 17 Apr 2009 19:55:29 -0700 (PDT) Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > @@ -742,7 +742,7 @@ static int uvc_alloc_urb_buffers(struct > > uvc_video_device *video, > > /* Buffers are already allocated, bail out. */ > > if (video->urb_size) > > - return 0; > > + return DIV_ROUND_UP(video->urb_size, psize); > > I don't think this is right. It should round _down_. > > It's supposed to return 'npackets', but if you pass it a different > packet size than it was passed originally, it can now return a > potentially bigger number than the already allocated buffer, no? > > So I think it should round down (ie use a regular divide). No? Yes,you are correct, please ignore my last reply, and following is the fixed patch. Thanks. >From a3b3d72cdd57a0699fb643b41b78eb7beb211ff5 Mon Sep 17 00:00:00 2001 From: Ming Lei <tom.leiming@xxxxxxxxx> Date: Wed, 15 Apr 2009 22:32:51 +0800 Subject: [PATCH] V4L/DVB:usbvideo:fix uvc resume failed(v2) Now urb buffers is not freed before suspend, so uvc_alloc_urb_buffers should return packet counts allocated originally during uvc resume , instead of zero. This version uses round down to return packet counts on Linus's suggestions, or else may lead to buffer destructed if packet size is changed before calling uvc_alloc_urb_buffers() in this kind of case. This patch is against v2.6.30-rc2. Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx> --- drivers/media/video/uvc/uvc_video.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c index a95e173..6ce974d 100644 --- a/drivers/media/video/uvc/uvc_video.c +++ b/drivers/media/video/uvc/uvc_video.c @@ -742,7 +742,7 @@ static int uvc_alloc_urb_buffers(struct uvc_video_device *video, /* Buffers are already allocated, bail out. */ if (video->urb_size) - return 0; + return video->urb_size / psize; /* Compute the number of packets. Bulk endpoints might transfer UVC * payloads accross multiple URBs. -- 1.6.0.GIT -- Lei Ming -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
