Re: [RESEND x2][PATCH 0/3] dwc2 fixes for edge cases on hikey

[Minas Harutyunyan]

Hi John Stultz,

On 10/20/2017 12:06 AM, John Stultz wrote:
> On Tue, Oct 17, 2017 at 1:41 AM, Minas Harutyunyan
> <Minas.Harutyunyan@xxxxxxxxxxxx> wrote:
>> On 10/17/2017 1:34 AM, John Stultz wrote:
>>> On Mon, Oct 16, 2017 at 1:36 AM, Minas Harutyunyan
>>> <Minas.Harutyunyan@xxxxxxxxxxxx> wrote:
>>>> On b-plug disconnect should asserted GOTGINT.SesEndDet interrupt.
>>>> According previously sent by you register dump (GHWCFG2 = 0x23affc70)
>>>> your core OTG_MODE=0.
>>>> Bellow fragment from programming guide on Device disconnect:
>>>>
>>>> "7.3Device Disconnection
>>>> The device session ends when the USB cable is disconnected or if the
>>>> VBUS is switched off by the Host. The
>>>> device disconnect flow varies depending on the value of the OTG_MODE
>>>> configuration parameter.
>>>>
>>>> When OTG_MODE = 0,1, or 3
>>>> When OTG_MODE is set to 0,1, or 3, the device disconnect flow is as follows:
>>>> 1. When the USB cable is unplugged or when the VBUS is switched off by
>>>> the Host, the Device core
>>>> trigger GINTSTS.OTGInt [bit 2] interrupt bit.
>>>> 2. When the device application detects GINTSTS.OTGInt interrupt, it
>>>> checks that the
>>>> GOTGINT.SesEndDet (Session End Detected) bit is set to 1’b1."
>>>>
>>>> So, you should receive and handle "Session End Detected". In function
>>>> dwc2_handle_otg_intr() on this interrupt (in device mode) calling
>>>> dwc2_hsotg_disconnect() function. By adding your patch "[PATCH 3/3] usb:
>>>> dwc2: Fix UDC state tracking" state changed to not attached as required.
>>>
>>>
>>> So, on the HiKey board (using 4.14-rc5 + Vardan's patch), I'm not
>>> seeing the GOTGINT_SES_END_DET in dwc2_handle_otg_intr() when I remove
>>> the USB OTG cable.
>>>
>>> In fact, I'm not seeing any calls to dwc2_handle_otg_intr()... which
>>> seems... odd maybe?  Any clues as to what might be going wrong then?
>>>
>>> thanks
>>> -john
>>>
>> Hi John Stultz,
>> So, on Hikey board on unplug B connector GOTGINT.SesEndDet interrupt not
>> asserted, instead asserted GINTSTS_CONIDSTSCHNG. Please, confirm.
> 
> Correct. On B unplug, I see:
> dwc2_handle_conn_id_status_change_intr: ++Connector ID Status Change
> Interrupt++  (Host)

I can't understand how on B unplug connector id status changed to host!
More probable it's board design issue. Please investigate hikey design.
Electrically Connector ID pin status changed when plugged A connector 
and when unplugged A connector because of in A connector internally 
ConnID pin connected to ground. In B connector ConnID pin floating.

> 
> And I never see any calls to dwc2_handle_otg_intr().
> 
>> In this case without your patch "[PATCH 1/3] usb: dwc2: Improve gadget
>> state disconnection handling" but by applying your patch "[PATCH 3/3]
>> usb: dwc2: Fix UDC state tracking":
>> 1. On B plug connect UDC state will be set to "configured"
>> 2. On B plug disconnect - "not attached".
>> Is it Ok for you?
> 

On our setup I tested your patch 3/3 without patches 1/3 and 2/3 and its 
changed state correctly.

> So this is what I expect, but I don't see it. Since without my patch,
> nothing seems to call disconenct when the B plug is disconnected, I
> still see:
>    # cat /sys/class/udc/f72c0000.usb/state
>    configured
> 
> thanks
> -john
>