Re: how to test g_webcam

[Roger Quadros <rogerq@ti.com>]

Hi,

On 14/10/2019 17:22, Felipe Balbi wrote:
> 
> 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.
> 

I used the a different uvc-gadget application from this location [1] and it seems to
work quite fine with builtin video pattern and jpg image but not with V4L2 capture source.

So something is broken in uvc-gadget at [2]

[1] https://github.com/wlhe/uvc-gadget
[2] http://git.ideasonboard.org/uvc-gadget.git

cheers,
-roger
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