Re: [PATCH] USB: uvc: add support for the Microsoft Surface Pro 3 Cameras

Laurent Pinchart
2015-11-09T17:33:19Z

Hi Denis,

On Thursday 11 June 2015 13:13:30 Dennis Chen wrote:
> > Could you please send me the output of 'lsusb -v -d 045e:07be' and
> > 'lsusb -v -
> > d 045e:07bf' (running as root if possible) ?
>
> Bus 001 Device 004: ID 045e:07bf Microsoft Corp.
> Device Descriptor:
> bLength 18
> bDescriptorType 1
> bcdUSB 2.00
> bDeviceClass 239 Miscellaneous Device
> bDeviceSubClass 2 ?
> bDeviceProtocol 1 Interface Association
> bMaxPacketSize0 64
> idVendor 0x045e Microsoft Corp.
> idProduct 0x07bf
> bcdDevice 21.52
> iManufacturer 1 QCM
> iProduct 2 Microsoft LifeCam Rear
> iSerial 0
> bNumConfigurations 1

[snip]

> Interface Descriptor:
> bLength 9
> bDescriptorType 4
> bInterfaceNumber 0
> bAlternateSetting 0
> bNumEndpoints 1
> bInterfaceClass 14 Video
> bInterfaceSubClass 1 Video Control
> bInterfaceProtocol 1
> iInterface 2 Microsoft LifeCam Rear

[snip]

I see where the problem comes from now. I had missed it before, but your
device sets the bInterfaceProtocol value to 1 as it's UVC 1.5 compliant, as
opposed to value 0 for UVC 1.1.

The uvcvideo driver doesn't support UVC 1.5 yet. It looks like your camera
supports the UVC 1.1 protocol as well, but that's not true of all UVC devices
in general. I expect that enabling detection of UVC 1.5 support in the driver
will result in issues with UVC 1.5 devices, but on the other hand those
devices are currently not supported at all. I'll thus submit a patch to enable
UVC 1.5 device detection, and we'll see how that goes. I'll CC you and would
appreciate if you could test the patch.