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Commit efc52a94 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
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V4L/DVB (9912): em28xx: fix/improve em28xx locking schema 



Changes/fixes on em28xx dev->lock:

- em28xx_init_dev() were unlocking without a previous lock;

- some read ioctls need to lock after the removal of KBL, since a write
  may be happening at the same time an ioctl is reading;

- keep the device locked during all device initialization;

- lock/unlock while reading/writing registers.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent cf8c91c3

drivers/media/video/em28xx/em28xx-video.c

+43 −12
Original line number Diff line number Diff line
@@ -784,10 +784,10 @@ static int vidioc_s_fmt_vid_cap(struct file *file, void *priv, 
	if (rc < 0)

		return rc;



	vidioc_try_fmt_vid_cap(file, priv, f);



	mutex_lock(&dev->lock);



	vidioc_try_fmt_vid_cap(file, priv, f);



	if (videobuf_queue_is_busy(&fh->vb_vidq)) {

		em28xx_errdev("%s queue busy\n", __func__);

		rc = -EBUSY;
@@ -828,15 +828,12 @@ static int vidioc_s_std(struct file *file, void *priv, v4l2_std_id * norm) 


	mutex_lock(&dev->lock);

	dev->norm = *norm;

	mutex_unlock(&dev->lock);



	/* Adjusts width/height, if needed */

	f.fmt.pix.width = dev->width;

	f.fmt.pix.height = dev->height;

	vidioc_try_fmt_vid_cap(file, priv, &f);



	mutex_lock(&dev->lock);



	/* set new image size */

	dev->width = f.fmt.pix.width;

	dev->height = f.fmt.pix.height;
@@ -966,11 +963,15 @@ static int vidioc_s_audio(struct file *file, void *priv, struct v4l2_audio *a) 
	struct em28xx_fh   *fh  = priv;

	struct em28xx      *dev = fh->dev;



	mutex_lock(&dev->lock);



	dev->ctl_ainput = INPUT(a->index)->amux;

	dev->ctl_aoutput = INPUT(a->index)->aout;



	if (!dev->ctl_aoutput)

		dev->ctl_aoutput = EM28XX_AOUT_MASTER;



	mutex_unlock(&dev->lock);

	return 0;

}
@@ -1019,6 +1020,7 @@ static int vidioc_g_ctrl(struct file *file, void *priv, 
	rc = check_dev(dev);

	if (rc < 0)

		return rc;



	mutex_lock(&dev->lock);



	if (!dev->board.has_msp34xx)
@@ -1129,8 +1131,10 @@ static int vidioc_g_frequency(struct file *file, void *priv, 
	struct em28xx_fh      *fh  = priv;

	struct em28xx         *dev = fh->dev;



	mutex_lock(&dev->lock);

	f->type = fh->radio ? V4L2_TUNER_RADIO : V4L2_TUNER_ANALOG_TV;

	f->frequency = dev->ctl_freq;

	mutex_unlock(&dev->lock);



	return 0;

}
@@ -1160,6 +1164,7 @@ static int vidioc_s_frequency(struct file *file, void *priv, 
	em28xx_i2c_call_clients(dev, VIDIOC_S_FREQUENCY, f);



	mutex_unlock(&dev->lock);



	return 0;

}
@@ -1187,15 +1192,20 @@ static int vidioc_g_register(struct file *file, void *priv, 
		return -EINVAL;



	if (em28xx_reg_len(reg->reg) == 1) {

		mutex_lock(&dev->lock);

		ret = em28xx_read_reg(dev, reg->reg);

		mutex_unlock(&dev->lock);



		if (ret < 0)

			return ret;



		reg->val = ret;

	} else {

		__le64 val = 0;

		mutex_lock(&dev->lock);

		ret = em28xx_read_reg_req_len(dev, USB_REQ_GET_STATUS,

						   reg->reg, (char *)&val, 2);

		mutex_unlock(&dev->lock);

		if (ret < 0)

			return ret;
@@ -1211,11 +1221,16 @@ static int vidioc_s_register(struct file *file, void *priv, 
	struct em28xx_fh      *fh  = priv;

	struct em28xx         *dev = fh->dev;

	__le64 buf;

	int    rc;



	buf = cpu_to_le64(reg->val);



	return em28xx_write_regs(dev, reg->reg, (char *)&buf,

	mutex_lock(&dev->lock);

	rc = em28xx_write_regs(dev, reg->reg, (char *)&buf,

			       em28xx_reg_len(reg->reg));

	mutex_unlock(&dev->lock);



	return rc;

}

#endif
@@ -1254,12 +1269,15 @@ static int vidioc_streamon(struct file *file, void *priv, 


	mutex_lock(&dev->lock);

	rc = res_get(fh);

	mutex_unlock(&dev->lock);



	if (unlikely(rc < 0))

		return rc;



	return (videobuf_streamon(&fh->vb_vidq));

	rc = videobuf_streamon(&fh->vb_vidq);



	mutex_unlock(&dev->lock);



	return rc;

}



static int vidioc_streamoff(struct file *file, void *priv,
@@ -1278,9 +1296,11 @@ static int vidioc_streamoff(struct file *file, void *priv, 
	if (type != fh->type)

		return -EINVAL;



	videobuf_streamoff(&fh->vb_vidq);

	mutex_lock(&dev->lock);



	videobuf_streamoff(&fh->vb_vidq);

	res_free(fh);



	mutex_unlock(&dev->lock);



	return 0;
@@ -1465,7 +1485,10 @@ static int radio_g_tuner(struct file *file, void *priv, 
	strcpy(t->name, "Radio");

	t->type = V4L2_TUNER_RADIO;



	mutex_lock(&dev->lock);

	em28xx_i2c_call_clients(dev, VIDIOC_G_TUNER, t);

	mutex_unlock(&dev->lock);



	return 0;

}
@@ -1497,7 +1520,9 @@ static int radio_s_tuner(struct file *file, void *priv, 
	if (0 != t->index)

		return -EINVAL;



	mutex_lock(&dev->lock);

	em28xx_i2c_call_clients(dev, VIDIOC_S_TUNER, t);

	mutex_unlock(&dev->lock);



	return 0;

}
@@ -1561,6 +1586,7 @@ static int em28xx_v4l2_open(struct inode *inode, struct file *filp) 
		}

	}

	mutex_unlock(&em28xx_devlist_mutex);



	if (NULL == dev)

		return -ENODEV;
@@ -2036,7 +2062,6 @@ static int em28xx_init_dev(struct em28xx **devhandle, struct usb_device *udev, 
	unsigned int maxh, maxw;



	dev->udev = udev;

	mutex_init(&dev->lock);

	mutex_init(&dev->ctrl_urb_lock);

	spin_lock_init(&dev->slock);

	init_waitqueue_head(&dev->open);
@@ -2151,7 +2176,6 @@ static int em28xx_init_dev(struct em28xx **devhandle, struct usb_device *udev, 
	return 0;



fail_reg_devices:

	mutex_unlock(&dev->lock);

	return retval;

}
@@ -2343,6 +2367,8 @@ static int em28xx_usb_probe(struct usb_interface *interface, 
		dev->model = card[nr];



	/* allocate device struct */

	mutex_init(&dev->lock);

	mutex_lock(&dev->lock);

	retval = em28xx_init_dev(&dev, udev, nr);

	if (retval) {

		em28xx_devused &= ~(1<<dev->devno);
@@ -2356,6 +2382,11 @@ static int em28xx_usb_probe(struct usb_interface *interface, 


	request_modules(dev);



	/* Should be the last thing to do, to avoid newer udev's to

	   open the device before fully initializing it

	 */

	mutex_unlock(&dev->lock);



	return 0;

}