From: Hans Verkuil <hans.verkuil@cisco.com>
Date: Wed, 6 Feb 2013 07:23:01 +0000 (-0300)
Subject: [media] stk-webcam: fix read() handling when reqbufs was already called
X-Git-Tag: firefly_0821_release~3680^2~618^2~563
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1b499fe506257369fd6059422989e36c71b99897;p=firefly-linux-kernel-4.4.55.git

[media] stk-webcam: fix read() handling when reqbufs was already called

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Arvydas Sidorenko <asido4@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
---

diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c b/drivers/media/usb/stkwebcam/stk-webcam.c
index 2f1a09db1135..a8fdbaf34720 100644
--- a/drivers/media/usb/stkwebcam/stk-webcam.c
+++ b/drivers/media/usb/stkwebcam/stk-webcam.c
@@ -654,7 +654,7 @@ static ssize_t stk_read(struct file *fp, char __user *buf,
 
 	if (!is_present(dev))
 		return -EIO;
-	if (dev->owner && dev->owner != fp)
+	if (dev->owner && (!dev->reading || dev->owner != fp))
 		return -EBUSY;
 	dev->owner = fp;
 	if (!is_streaming(dev)) {
@@ -662,6 +662,7 @@ static ssize_t stk_read(struct file *fp, char __user *buf,
 			|| stk_allocate_buffers(dev, 3)
 			|| stk_start_stream(dev))
 			return -ENOMEM;
+		dev->reading = 1;
 		spin_lock_irqsave(&dev->spinlock, flags);
 		for (i = 0; i < dev->n_sbufs; i++) {
 			list_add_tail(&dev->sio_bufs[i].list, &dev->sio_avail);
diff --git a/drivers/media/usb/stkwebcam/stk-webcam.h b/drivers/media/usb/stkwebcam/stk-webcam.h
index 03550cf60dcd..9bbfa3d9bfdd 100644
--- a/drivers/media/usb/stkwebcam/stk-webcam.h
+++ b/drivers/media/usb/stkwebcam/stk-webcam.h
@@ -118,6 +118,7 @@ struct stk_camera {
 
 	int frame_size;
 	/* Streaming buffers */
+	int reading;
 	unsigned int n_sbufs;
 	struct stk_sio_buffer *sio_bufs;
 	struct list_head sio_avail;