From 64ea37bbd8a5815522706f0099ad3f11c7537e15 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Sun, 8 Jun 2014 13:54:57 -0300 Subject: [PATCH] [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 --- 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 4aa1d7a1641b..85d83ca5a4cd 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; -- GitLab