Re: g_webcam Isoch high bandwidth transfer

[Felipe Balbi <felipe.balbi@linux.intel.com>]

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Hi,

yfw <nh26223@gmail.com> writes:
>>>>>> Here's one that actually compiles, sorry about that.
>>>>>
>>>>> No worries, I was sleeping ;-)
>>>>>
>>>>> I will test it out early next week. Thanks.
>>>>
>>>> meanwhile, how about some instructions on how to test this out myself?
>>>> How are you using g_webcam and what are you running on host side? Got a
>>>> nice list of commands there I can use? I think I can get to bottom of
>>>> this much quicker if I can reproduce it locally ;-)
>>>
>>> On device side:
>>> - first patch g_webcam as in my first email in this thread to enable
>>>   640x480@30fps;
>>> - # modprobe g_webcam streaming_maxpacket=3072
>>> - then run uvc-gadget to feed the YUV frames;
>>> 	http://git.ideasonboard.org/uvc-gadget.git
>>
>> as is, g_webcam never enumerates to the host. It's calls to
>> usb_function_active() and usb_function_deactivate() are unbalanced. Do
>> you have any other changes to g_webcam?
> With uvc function gadget driver, user daemon uvc-gadget must be started
> before connect to host. Not sure whether g_webcam has same requirement.

f_uvc.c should be handling that by means for usb_function_deactivate().

I'll try keeping cable disconnected until uvc-gadget is running.

>> Also, uvc-gadget.git doesn't compile, had to modify it a bit:
>>
>> -#include "../drivers/usb/gadget/uvc.h"
>> +#include "../drivers/usb/gadget/function/uvc.h"
>>
>> Also fixed a build warning:
>>
>> @@ -732,6 +732,8 @@ int main(int argc, char *argv[])
>>                 fd_set wfds = fds;
>>
>>                 ret = select(dev->fd + 1, NULL, &wfds, &efds, NULL);
>> +               if (ret < 0)
>> +                       return ret;
>>                 if (FD_ISSET(dev->fd, &efds))
>>                         uvc_events_process(dev);
>>                 if (FD_ISSET(dev->fd, &wfds))
>>
>> Laurent, have you tested g_webcam recently? What's the magic to get it
>> working?
>>
>> Here's what I get out of dmesg:
>>
>> [   58.568380] usb 1-9: new high-speed USB device number 5 using xhci_hcd
>> [   58.738680] usb 1-9: New USB device found, idVendor=1d6b, idProduct=0102
>> [   58.738683] usb 1-9: New USB device strings: Mfr=1, Product=2, SerialNumber=0
>> [   58.738685] usb 1-9: Product: Webcam gadget
>> [   58.738687] usb 1-9: Manufacturer: Linux Foundation
>> [   58.739133] g_webcam gadget: high-speed config #1: Video
>> [   58.739138] g_webcam gadget: uvc_function_set_alt(0, 0)
>> [   58.739139] g_webcam gadget: reset UVC Control
>> [   58.739149] g_webcam gadget: uvc_function_set_alt(1, 0)
>> [   58.804369] uvcvideo: Found UVC 1.00 device Webcam gadget (1d6b:0102)
>> [   58.804479] g_webcam gadget: uvc_function_set_alt(1, 0)
>> [   64.188459] uvcvideo: UVC non compliance - GET_DEF(PROBE) not supported. Enabling workaround.
> Looks like you connect your usb device to your usb host port on same
> board. Nice.

yeah, that helps.

> The GET_DEF is handled by user daemon uvc-gadget. It may be related.

okay.

-- 
balbi

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