From 009a90597e177320e47154dd0817d201f52bcd46 Mon Sep 17 00:00:00 2001 From: Brandon Philips Date: Wed, 2 Apr 2008 18:10:59 -0300 Subject: [PATCH] V4L/DVB (7488): videobuf: Simplify videobuf_waiton logic and possibly avoid missed wakeup 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 Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/videobuf-core.c | 37 ++++++++++++----------------- 1 file changed, 15 insertions(+), 22 deletions(-) diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c index e4a864e0d96b..1ba3aaa29dd0 100644 --- a/drivers/media/video/videobuf-core.c +++ b/drivers/media/video/videobuf-core.c @@ -64,32 +64,25 @@ void *videobuf_alloc(struct videobuf_queue *q) 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, -- GitLab