Re: how to test g_webcam

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

Hi,

Roger Quadros <rogerq@ti.com> writes:
>> Hmm, Link Change is disabled by default upstream, unless you're running
>> on anything older than 2.50a. I don't remember the version you're using,
>> though :-p
>
> 2.02a

Thanks :-)

>>>       irq/170-dwc3-270   [000] d...   173.408918: dwc3_event: event (00000101): Reset [U0]
>>>       irq/170-dwc3-270   [000] d...   173.463787: dwc3_event: event (00000201): Connection Done [U0]
>>>       irq/170-dwc3-270   [000] d...   173.463796: dwc3_gadget_ep_cmd: ep0out: cmd 'Set Endpoint Configuration' [401] params 80000200 00000500 00000000 --> status: Successful
>>>       irq/170-dwc3-270   [000] d...   173.463799: dwc3_gadget_ep_enable: ep0out: mps 64/512 streams 0 burst 1 ring 0/0 flags E:swBp:>
>>>       irq/170-dwc3-270   [000] d...   173.463803: dwc3_gadget_ep_cmd: ep0in: cmd 'Set Endpoint Configuration' [401] params 80000200 02000500 00000000 --> status: Successful
>>>       irq/170-dwc3-270   [000] d...   173.463804: dwc3_gadget_ep_enable: ep0in: mps 64/512 streams 0 burst 1 ring 0/0 flags E:swbp:<
>> 
>> hmm, High speed? Can we get traces for superspeed too?
>
> We can after I figure out the -ENODEV issue I reported above.

cool

>>>         uvc-gadget-275   [001] d...   173.712586: dwc3_prepare_trb: ep0out: trb 4a151d32 buf 00000000ae85b000 size 8 ctrl 00000c23 (HLcs:SC:setup)
>>>         uvc-gadget-275   [001] d...   173.712592: dwc3_gadget_ep_cmd: ep0out: cmd 'Start Transfer' [406] params 00000000 ae85b000 00000000 --> status: Successful
>>>       irq/170-dwc3-270   [000] d...   173.712688: dwc3_event: event (0000c040): ep0out: Transfer Complete (sIL) [Setup Phase]
>>>       irq/170-dwc3-270   [000] d...   173.712690: dwc3_ctrl_req: a1 81 00 02 00 00 01 00
>> 
>> Another one...
>
> 0xa1 GetRequest directed to video data endpoint of a VideoStreaming interface,
> 0x81 GET_CUR (Current setting attribute),
> 0002 CT_AE_MODE_CONTROL (Auto-exposure control selector),
> 0000 interface?,
> length 0001,

Thanks for these :-)

>>>         uvc-gadget-275   [001] d...   215.933842: dwc3_gadget_ep_cmd: ep1in: cmd 'End Transfer' [30c08] params 00000000 00000000 00000000 --> status: Successful
>>>         uvc-gadget-275   [001] .n..   215.933980: dwc3_ep_dequeue: ep2in: req f1fb458c length 0/1024 zsI ==> -11
>>>         uvc-gadget-275   [001] .n..   215.940651: dwc3_ep_dequeue: ep2in: req 5be7fd9f length 0/1024 zsI ==> -11
>>>         uvc-gadget-275   [001] .n..   215.947297: dwc3_ep_dequeue: ep2in: req 996abf23 length 0/1024 zsI ==> -11
>>>         uvc-gadget-275   [001] .n..   215.953954: dwc3_ep_dequeue: ep2in: req d9961026 length 0/1024 zsI ==> -11
>>>         uvc-gadget-275   [001] .n..   215.960615: dwc3_free_request: ep2in: req f1fb458c length 0/1024 zsI ==> -11
>>>         uvc-gadget-275   [001] .n..   215.960617: dwc3_free_request: ep2in: req 5be7fd9f length 0/1024 zsI ==> -11
>>>         uvc-gadget-275   [001] .n..   215.960618: dwc3_free_request: ep2in: req 996abf23 length 0/1024 zsI ==> -11
>>>         uvc-gadget-275   [001] .n..   215.960619: dwc3_free_request: ep2in: req d9961026 length 0/1024 zsI ==> -11
>> 
>> So, first things first:
>> 
>> Let's figure out what those class requests are and why are they *always*
>> stalled. UVC class spec should answer that.
>
> I tried to decipher 2 class specific requests that we get.
>
>> 
>> Then we need to find out why it takes 1.5 seconds for uvc-gadget to
>> queue more data.
>> 
>
> Not sure how to do that.

Look at the source for uvc-gadget. If I were to guess, I'd say
uvc-gadget prepares frames as a function of the requested bandwidth.

It probably goes to sleep periodically until it thinks there's more data
to send.

Best

-- 
balbi