From a2d887c5fea33f341fd0d2a1487150473cf69014 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Mon, 7 May 2012 08:19:42 -0300 Subject: [PATCH] [media] gspca: Use req_events in poll So that we don't start a read stream when an app is only polling for control events. Signed-off-by: Hans de Goede Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/gspca/gspca.c | 44 +++++++++++++++++++++++---------------- 1 file changed, 26 insertions(+), 18 deletions(-) diff --git a/drivers/media/video/gspca/gspca.c b/drivers/media/video/gspca/gspca.c index d9df309..8b97f77 100644 --- a/drivers/media/video/gspca/gspca.c +++ b/drivers/media/video/gspca/gspca.c @@ -2030,31 +2030,39 @@ out: static unsigned int dev_poll(struct file *file, poll_table *wait) { struct gspca_dev *gspca_dev = video_drvdata(file); - int ret; + unsigned long req_events = poll_requested_events(wait); + int ret = 0; PDEBUG(D_FRAM, "poll"); - poll_wait(file, &gspca_dev->wq, wait); + if (req_events & POLLPRI) + ret |= v4l2_ctrl_poll(file, wait); - /* if reqbufs is not done, the user would use read() */ - if (gspca_dev->memory == GSPCA_MEMORY_NO) { - ret = read_alloc(gspca_dev, file); - if (ret != 0) - return POLLERR; - } + if (req_events & (POLLIN | POLLRDNORM)) { + /* if reqbufs is not done, the user would use read() */ + if (gspca_dev->memory == GSPCA_MEMORY_NO) { + if (read_alloc(gspca_dev, file) != 0) { + ret |= POLLERR; + goto out; + } + } - if (mutex_lock_interruptible(&gspca_dev->queue_lock) != 0) - return POLLERR; + poll_wait(file, &gspca_dev->wq, wait); - /* check if an image has been received */ - if (gspca_dev->fr_o != atomic_read(&gspca_dev->fr_i)) - ret = POLLIN | POLLRDNORM; /* yes */ - else - ret = 0; - ret |= v4l2_ctrl_poll(file, wait); - mutex_unlock(&gspca_dev->queue_lock); + /* check if an image has been received */ + if (mutex_lock_interruptible(&gspca_dev->queue_lock) != 0) { + ret |= POLLERR; + goto out; + } + if (gspca_dev->fr_o != atomic_read(&gspca_dev->fr_i)) + ret |= POLLIN | POLLRDNORM; + mutex_unlock(&gspca_dev->queue_lock); + } + +out: if (!gspca_dev->present) - return POLLHUP; + ret |= POLLHUP; + return ret; } -- 2.7.4