From: brandon@ifup.org
To: mchehab@infradead.org
Cc: video4linux-list@redhat.com, v4l-dvb-maintainer@linuxtv.org,
Brandon Philips <bphilips@suse.de>
Subject: [patch 4/9] videobuf: Simplify videobuf_waiton logic and possibly avoid missed wakeup
Date: Fri, 28 Mar 2008 02:39:48 -0700 [thread overview]
Message-ID: <20080328094021.647427486@ifup.org> (raw)
In-Reply-To: 20080328093944.278994792@ifup.org
[-- Attachment #1: simplify-videobuf_waiton-logic.patch --]
[-- Type: text/plain, Size: 1961 bytes --]
Possible missed wakeup- use kernel helpers for wait queues
http://www.mail-archive.com/linux-usb-devel@lists.sourceforge.net/msg27983.html
Signed-off-by: Brandon Philips <bphilips@suse.de>
---
linux/drivers/media/video/videobuf-core.c | 37 ++++++++++++------------------
1 file changed, 15 insertions(+), 22 deletions(-)
Index: v4l-dvb/linux/drivers/media/video/videobuf-core.c
===================================================================
--- v4l-dvb.orig/linux/drivers/media/video/videobuf-core.c
+++ v4l-dvb/linux/drivers/media/video/videobuf-core.c
@@ -65,32 +65,25 @@ void *videobuf_alloc(struct videobuf_que
return vb;
}
+#define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\
+ vb->state != VIDEOBUF_QUEUED)
int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
{
- int retval = 0;
- DECLARE_WAITQUEUE(wait, current);
-
MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
- add_wait_queue(&vb->done, &wait);
- while (vb->state == VIDEOBUF_ACTIVE || vb->state == VIDEOBUF_QUEUED) {
- if (non_blocking) {
- retval = -EAGAIN;
- break;
- }
- set_current_state(intr ? TASK_INTERRUPTIBLE
- : TASK_UNINTERRUPTIBLE);
- if (vb->state == VIDEOBUF_ACTIVE ||
- vb->state == VIDEOBUF_QUEUED)
- schedule();
- set_current_state(TASK_RUNNING);
- if (intr && signal_pending(current)) {
- dprintk(1, "buffer waiton: -EINTR\n");
- retval = -EINTR;
- break;
- }
+
+ if (non_blocking) {
+ if (WAITON_CONDITION)
+ return 0;
+ else
+ return -EAGAIN;
}
- remove_wait_queue(&vb->done, &wait);
- return retval;
+
+ if (intr)
+ return wait_event_interruptible(vb->done, WAITON_CONDITION);
+ else
+ wait_event(vb->done, WAITON_CONDITION);
+
+ return 0;
}
int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
--
--
video4linux-list mailing list
Unsubscribe mailto:video4linux-list-request@redhat.com?subject=unsubscribe
https://www.redhat.com/mailman/listinfo/video4linux-list
next prev parent reply other threads:[~2008-03-28 9:39 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-28 9:39 [patch 0/9] videobuf fixes 2.6.25 brandon
2008-03-28 9:39 ` [patch 1/9] soc_camera: Introduce a spinlock for use with videobuf brandon
2008-03-28 9:39 ` [patch 2/9] videobuf: Require spinlocks for all videobuf users brandon
2008-03-28 9:39 ` [patch 3/9] videobuf: Wakeup queues after changing the state to ERROR brandon
2008-03-28 9:39 ` brandon [this message]
2008-03-28 9:39 ` [patch 5/9] videobuf-vmalloc.c: Remove buf_release from videobuf_vm_close brandon
2008-03-28 9:39 ` [patch 6/9] videobuf-vmalloc.c: Fix hack of postponing mmap on remap failure brandon
2008-03-28 9:39 ` [patch 7/9] vivi: Simplify the vivi driver and avoid deadlocks brandon
2008-03-28 9:39 ` [patch 8/9] videobuf: Avoid deadlock with QBUF and bring up to spec for empty queue brandon
2008-03-28 9:39 ` [patch 9/9] videobuf-dma-sg.c: Avoid NULL dereference and add comment about backwards compatibility brandon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20080328094021.647427486@ifup.org \
--to=brandon@ifup.org \
--cc=bphilips@suse.de \
--cc=mchehab@infradead.org \
--cc=v4l-dvb-maintainer@linuxtv.org \
--cc=video4linux-list@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox