releases/3.16.3/media-au0828-only-alt-setting-logic-when-needed.patch

   1 From 64ea37bbd8a5815522706f0099ad3f11c7537e15 Mon Sep 17 00:00:00 2001
   2 From: Mauro Carvalho Chehab <m.chehab@samsung.com>
   3 Date: Sun, 8 Jun 2014 13:54:57 -0300
   4 Subject: media: au0828: Only alt setting logic when needed
   5
   6 From: Mauro Carvalho Chehab <m.chehab@samsung.com>
   7
   8 commit 64ea37bbd8a5815522706f0099ad3f11c7537e15 upstream.
   9
  10 It seems that there's a bug at au0828 hardware/firmware
  11 related to alternate setting: when the device is already at
  12 alt 5, a further call causes the URBs to receive -ESHUTDOWN.
  13
  14 I found two different encarnations of this issue:
  15
  16 1) at qv4l2, it fails the second time we try to open the
  17 video screen;
  18 2) at xawtv, when audio underrun occurs, with is very
  19 frequent, at least on my test machine.
  20
  21 The fix is simple: just check if alt=5 before calling
  22 set_usb_interface().
  23
  24 Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
  25 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  26
  27 ---
  28  drivers/media/usb/au0828/au0828-video.c |   34 ++++++++++++++++----------------
  29  1 file changed, 17 insertions(+), 17 deletions(-)
  30
  31 --- a/drivers/media/usb/au0828/au0828-video.c
  32 +++ b/drivers/media/usb/au0828/au0828-video.c
  33 @@ -787,11 +787,27 @@ static int au0828_i2s_init(struct au0828
  34
  35  /*
  36   * Auvitek au0828 analog stream enable
  37 - * Please set interface0 to AS5 before enable the stream
  38   */
  39  static int au0828_analog_stream_enable(struct au0828_dev *d)
  40  {
  41 +       struct usb_interface *iface;
  42 +       int ret;
  43 +
  44         dprintk(1, "au0828_analog_stream_enable called\n");
  45 +
  46 +       iface = usb_ifnum_to_if(d->usbdev, 0);
  47 +       if (iface && iface->cur_altsetting->desc.bAlternateSetting != 5) {
  48 +               dprintk(1, "Changing intf#0 to alt 5\n");
  49 +               /* set au0828 interface0 to AS5 here again */
  50 +               ret = usb_set_interface(d->usbdev, 0, 5);
  51 +               if (ret < 0) {
  52 +                       printk(KERN_INFO "Au0828 can't set alt setting to 5!\n");
  53 +                       return -EBUSY;
  54 +               }
  55 +       }
  56 +
  57 +       /* FIXME: size should be calculated using d->width, d->height */
  58 +
  59         au0828_writereg(d, AU0828_SENSORCTRL_VBI_103, 0x00);
  60         au0828_writereg(d, 0x106, 0x00);
  61         /* set x position */
  62 @@ -1002,15 +1018,6 @@ static int au0828_v4l2_open(struct file
  63                 return -ERESTARTSYS;
  64         }
  65         if (dev->users == 0) {
  66 -               /* set au0828 interface0 to AS5 here again */
  67 -               ret = usb_set_interface(dev->usbdev, 0, 5);
  68 -               if (ret < 0) {
  69 -                       mutex_unlock(&dev->lock);
  70 -                       printk(KERN_INFO "Au0828 can't set alternate to 5!\n");
  71 -                       kfree(fh);
  72 -                       return -EBUSY;
  73 -               }
  74 -
  75                 au0828_analog_stream_enable(dev);
  76                 au0828_analog_stream_reset(dev);
  77
  78 @@ -1252,13 +1259,6 @@ static int au0828_set_format(struct au08
  79                 }
  80         }
  81
  82 -       /* set au0828 interface0 to AS5 here again */
  83 -       ret = usb_set_interface(dev->usbdev, 0, 5);
  84 -       if (ret < 0) {
  85 -               printk(KERN_INFO "Au0828 can't set alt setting to 5!\n");
  86 -               return -EBUSY;
  87 -       }
  88 -
  89         au0828_analog_stream_enable(dev);
  90
  91         return 0;