From 45053edc054ac9467adfdaf4f8a39db15af22b37 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Fri, 28 Aug 2015 08:48:28 -0300 Subject: [PATCH] [media] saa7164: fix poll bugs - poll doesn't return negative values, so you can't return -EINVAL. Instead return POLLERR. - poll can't be called if !video_is_registered(), so this test can be dropped. - poll can never do a blocking wait, so remove that check. - poll shouldn't attempt to start streaming if the caller isn't interested in read events. Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/pci/saa7164/saa7164-encoder.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/drivers/media/pci/saa7164/saa7164-encoder.c b/drivers/media/pci/saa7164/saa7164-encoder.c index 96dd1e483c79..fd32fa0c8cb7 100644 --- a/drivers/media/pci/saa7164/saa7164-encoder.c +++ b/drivers/media/pci/saa7164/saa7164-encoder.c @@ -915,6 +915,7 @@ static ssize_t fops_read(struct file *file, char __user *buffer, static unsigned int fops_poll(struct file *file, poll_table *wait) { + unsigned long req_events = poll_requested_events(wait); struct saa7164_encoder_fh *fh = (struct saa7164_encoder_fh *)file->private_data; struct saa7164_port *port = fh->port; @@ -928,26 +929,18 @@ static unsigned int fops_poll(struct file *file, poll_table *wait) saa7164_histogram_update(&port->poll_interval, port->last_poll_msecs_diff); - if (!video_is_registered(port->v4l_device)) - return -EIO; + if (!(req_events & (POLLIN | POLLRDNORM))) + return mask; if (atomic_cmpxchg(&fh->v4l_reading, 0, 1) == 0) { if (atomic_inc_return(&port->v4l_reader_count) == 1) { if (saa7164_encoder_initialize(port) < 0) - return -EINVAL; + return POLLERR; saa7164_encoder_start_streaming(port); msleep(200); } } - /* blocking wait for buffer */ - if ((file->f_flags & O_NONBLOCK) == 0) { - if (wait_event_interruptible(port->wait_read, - saa7164_enc_next_buf(port))) { - return -ERESTARTSYS; - } - } - /* Pull the first buffer from the used list */ if (!list_empty(&port->list_buf_used.list)) mask |= POLLIN | POLLRDNORM; -- 2.45.2