[media] au0828: Only alt setting logic when needed

It seems that there's a bug at au0828 hardware/firmware
related to alternate setting: when the device is already at
alt 5, a further call causes the URBs to receive -ESHUTDOWN.

I found two different encarnations of this issue:

1) at qv4l2, it fails the second time we try to open the
video screen;
2) at xawtv, when audio underrun occurs, with is very
frequent, at least on my test machine.

The fix is simple: just check if alt=5 before calling
set_usb_interface().

Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
This commit is contained in:
Mauro Carvalho Chehab 2014-06-08 13:54:57 -03:00
parent f2fd7ce6f2
commit 64ea37bbd8

View File

@ -787,11 +787,27 @@ static int au0828_i2s_init(struct au0828_dev *dev)
/*
* Auvitek au0828 analog stream enable
* Please set interface0 to AS5 before enable the stream
*/
static int au0828_analog_stream_enable(struct au0828_dev *d)
{
struct usb_interface *iface;
int ret;
dprintk(1, "au0828_analog_stream_enable called\n");
iface = usb_ifnum_to_if(d->usbdev, 0);
if (iface && iface->cur_altsetting->desc.bAlternateSetting != 5) {
dprintk(1, "Changing intf#0 to alt 5\n");
/* set au0828 interface0 to AS5 here again */
ret = usb_set_interface(d->usbdev, 0, 5);
if (ret < 0) {
printk(KERN_INFO "Au0828 can't set alt setting to 5!\n");
return -EBUSY;
}
}
/* FIXME: size should be calculated using d->width, d->height */
au0828_writereg(d, AU0828_SENSORCTRL_VBI_103, 0x00);
au0828_writereg(d, 0x106, 0x00);
/* set x position */
@ -1002,15 +1018,6 @@ static int au0828_v4l2_open(struct file *filp)
return -ERESTARTSYS;
}
if (dev->users == 0) {
/* set au0828 interface0 to AS5 here again */
ret = usb_set_interface(dev->usbdev, 0, 5);
if (ret < 0) {
mutex_unlock(&dev->lock);
printk(KERN_INFO "Au0828 can't set alternate to 5!\n");
kfree(fh);
return -EBUSY;
}
au0828_analog_stream_enable(dev);
au0828_analog_stream_reset(dev);
@ -1252,13 +1259,6 @@ static int au0828_set_format(struct au0828_dev *dev, unsigned int cmd,
}
}
/* set au0828 interface0 to AS5 here again */
ret = usb_set_interface(dev->usbdev, 0, 5);
if (ret < 0) {
printk(KERN_INFO "Au0828 can't set alt setting to 5!\n");
return -EBUSY;
}
au0828_analog_stream_enable(dev);
return 0;