[PATCH 3.13 054/187] [media] au0828: Only alt setting logic when needed

Kamal Mostafa
2014-09-15T22:13:27Z

From: Mauro Carvalho Chehab <m.chehab@samsung.com>

commit 64ea37bbd8a5815522706f0099ad3f11c7537e15 upstream.

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().

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
drivers/media/usb/au0828/au0828-video.c | 34 ++++++++++++++++-----------------
1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/drivers/media/usb/au0828/au0828-video.c b/drivers/media/usb/au0828/au0828-video.c
index f615454..7ed75ef 100644
--- a/drivers/media/usb/au0828/au0828-video.c
+++ b/drivers/media/usb/au0828/au0828-video.c
@@ -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;
--
1.9.1