Re: [PATCH] usb: gadget: function: acm: return zlp for OUT setup

[Felipe Balbi <balbi@ti.com>]

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Hi,

Jassi Brar <jassisinghbrar@gmail.com> writes:
> On Wed, Oct 14, 2015 at 8:42 PM, Felipe Balbi <balbi@ti.com> wrote:
>>
>> Hi,
>>
>> jaswinder.singh@linaro.org writes:
>>> From: Jassi Brar <jaswinder.singh@linaro.org>
>>>
>>> We must return 0 for any OUT setup request, otherwise
>>> protocol error may occur.
>>
>> have you seen any such errors ?
>>
> Yes. While testing my new udc driver.
>
>
>> Care to describe what problems you have seen and which UDC you were using,
>> what's the exact scenario. How have you tested this ?
>>
> The udc I am writing the driver for is not yet public. To test my
> driver at lowest level possible, I use 'usbmon' to capture and analyze
> traffic since I don't have any hardware probe.
>
> I see the following on gadget side
> -------
> configfs-gadget gadget: non-core control req21.20 v0000 i0001 l7
> configfs-gadget gadget: acm ttyGS0 req21.20 v0000 i0001 l7
> configfs-gadget gadget: acm ttyGS0 completion, err -71
> -------
>
> and the following on host side usbmon capture
> -------
> ffff88041ed01f00 540296433 S Co:3:023:0 s 21 20 0000 0001 0007 7 =
> 80250000 000008
> ffff88041ed01f00 540296790 C Co:3:023:0 -71 0
> -------

and you did you even consider this could be a bug in your new UDC driver
at all ? This works fine with other UDCs.

How far are you in developing this new UDC driver ? Did you run USBCV at
all ? Are you sure you're implementing EP0 handling correctly ? What
sort of tests have you done with this UDC ? Is it working with testusb
against a known good host (EHCI and XHCI should be good for that) ?

-- 
balbi

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