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V4L/DVB (9912): em28xx: fix/improve em28xx locking schema

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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: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Mauro Carvalho Chehab 2008-12-16 22:04:56 -03:00
parent cf8c91c3e7
commit efc52a9484
1 changed files with 43 additions and 12 deletions
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55
drivers/media/video/em28xx/em28xx-video.c
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@ -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,
em28xx_reg_len(reg->reg));
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;
}