From: Arnd Bergmann Date: Wed, 26 Feb 2014 11:01:48 +0000 (-0300) Subject: [media] arv: fix sleep_on race X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=f97881fe500026053c24d2a0ef8aebfd3c2a1ca8;p=openwrt%2Fstaging%2Fblogic.git [media] arv: fix sleep_on race interruptible_sleep_on is racy and going away. In the arv driver that race has probably never caused problems since it would require a whole video frame to be captured before the read function has a chance to go to sleep, but using wait_event_interruptible lets us kill off the old interface. In order to do this, we have to slightly adapt the meaning of the ar->start_capture field to distinguish between not having started a frame and having completed it. Signed-off-by: Arnd Bergmann Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/platform/arv.c b/drivers/media/platform/arv.c index e346d32d08ce..e9410e41ae0c 100644 --- a/drivers/media/platform/arv.c +++ b/drivers/media/platform/arv.c @@ -109,7 +109,7 @@ extern struct cpuinfo_m32r boot_cpu_data; struct ar { struct v4l2_device v4l2_dev; struct video_device vdev; - unsigned int start_capture; /* duaring capture in INT. mode. */ + int start_capture; /* duaring capture in INT. mode. */ #if USE_INT unsigned char *line_buff; /* DMA line buffer */ #endif @@ -307,11 +307,11 @@ static ssize_t ar_read(struct file *file, char *buf, size_t count, loff_t *ppos) /* * Okay, kick AR LSI to invoke an interrupt */ - ar->start_capture = 0; + ar->start_capture = -1; ar_outl(arvcr1 | ARVCR1_HIEN, ARVCR1); local_irq_restore(flags); /* .... AR interrupts .... */ - interruptible_sleep_on(&ar->wait); + wait_event_interruptible(ar->wait, ar->start_capture == 0); if (signal_pending(current)) { printk(KERN_ERR "arv: interrupted while get frame data.\n"); ret = -EINTR;