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| author | Hans de Goede <hdegoede@redhat.com> | 2011-10-09 10:28:27 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2012-03-27 11:42:04 -0300 |
| commit | 296da3cd14db9eb5606924962b2956c9c656dbb0 (patch) | |
| tree | ba0e1014a0aca90e7a0b1e58047fd610ad84db7a /drivers/media/video/pwc | |
| parent | 0bf0f713d6e6b9f1c510d598c29ac17812a4eea5 (diff) | |
| download | lwn-296da3cd14db9eb5606924962b2956c9c656dbb0.tar.gz lwn-296da3cd14db9eb5606924962b2956c9c656dbb0.zip | |
[media] pwc: poll(): Check that the device has not beem claimed for streaming already
Some apps which use read() start the streaming through a call to poll(),
this means that if another app has already claimed the device for streaming
(through for example a s_fmt, or a reqbufs), that the poll should fail instead
of getting passed through to vb2_poll.
We only check for this when the app is polling for reads, so that ctrl events
still work.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/pwc')
| -rw-r--r-- | drivers/media/video/pwc/pwc-if.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/media/video/pwc/pwc-if.c b/drivers/media/video/pwc/pwc-if.c index 122fbd0081eb..f3370a87cbc0 100644 --- a/drivers/media/video/pwc/pwc-if.c +++ b/drivers/media/video/pwc/pwc-if.c @@ -625,10 +625,19 @@ static ssize_t pwc_video_read(struct file *file, char __user *buf, static unsigned int pwc_video_poll(struct file *file, poll_table *wait) { struct pwc_device *pdev = video_drvdata(file); + unsigned long req_events = poll_requested_events(wait); if (!pdev->udev) return POLL_ERR; + if ((req_events & (POLLIN | POLLRDNORM)) && + pdev->vb_queue.num_buffers == 0 && + !pdev->iso_init) { + /* This poll will start a read stream, check capt_file */ + if (pwc_test_n_set_capt_file(pdev, file)) + return POLL_ERR; + } + return vb2_poll(&pdev->vb_queue, file, wait); } |