Re: [PATCH] usb: dwc2: gadget: On disconnect reset device address to zero

[Felipe Balbi <balbi@kernel.org>]

Hi,

Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> writes:
>>> Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> writes:
>>>> USB CV driver stack doesn't perform USB RESET after device disconnect/
>>>> connect, so need to reset to zero DEVADDR field in DCFG to pass
>>>> enumeration again.
>>>>
>>>> Signed-off-by: Minas Harutyunyan <hminas@synopsys.com>
>>>> ---
>>>>  drivers/usb/dwc2/gadget.c | 3 +++
>>>>  1 file changed, 3 insertions(+)
>>>>
>>>> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
>>>> index 98a4a79e7f6e..deb3d901b99d 100644
>>>> --- a/drivers/usb/dwc2/gadget.c
>>>> +++ b/drivers/usb/dwc2/gadget.c
>>>> @@ -3174,6 +3174,9 @@ void dwc2_hsotg_disconnect(struct dwc2_hsotg *hsotg)
>>>>  		return;
>>>>
>>>>  	hsotg->connected = 0;
>>>> +	/* On disconnect reset device address to zero */
>>>> +	__bic32(hsotg->regs + DCFG, DCFG_DEVADDR_MASK);
>>>> +
>>>
>>> Which of the tests are you talking about? Which particular USB CV are
>>> you running?
>>>
>>> I don't remember ever seeing this with dwc3. How should I go about
>>> triggering this problem? If this was really the case, then we would have
>>> this on *all* UDCs.
>>>
>>> I just did a fresh install of USB 3 Gen X CV (that I just download from
>>> usb.org). Ran Chapter 9 tests against a HS dwc3 board I have around and
>>> I can't see the problem you're talking about.
>>>
>>> Here are all my non-endpoint interrupt events in order. Test passes
>>> fine. If disconnect, reconnect and run the tests again, then Reset will
>>> be driven on the bus which will cause address to be reset.
>>>
>>> Can you share more details about the problem you're facing?
>>
>> I've been looking at dwc2 for a while and I think this is a bug in
>> dwc2_hsotg_irq() on the branch for GINTSTS_USBRST. I don't have docs for
>> dwc2.
>>
>
> USB RESET not issuing by CV host stack after connect. Below dmesg:
>
> Disconnect
>
> [23984.039199] dwc2 dwc2.1.auto: dwc2_hsotg_irq: 04008428 00000400 
> (d0bc3cc4) retry 8
> [23984.039204] dwc2 dwc2.1.auto: GINTSTS_ErlySusp
> [23984.042235] dwc2 dwc2.1.auto: gintsts=04008828  gintmsk=d0bc3cc4
> [23984.042240] dwc2 dwc2.1.auto: USB SUSPEND
> [23984.042247] dwc2 dwc2.1.auto: DSTS=0x5f4c01
> [23984.042250] dwc2 dwc2.1.auto: DSTS.Suspend Status=1 HWCFG4.Power 
> Optimize=0
> [23984.042260] dwc2 dwc2.1.auto: dwc2_hsotg_irq: 04008028 00000000 
> (d0bc3cc4) retry 8
> [23984.272308] dwc2 dwc2.1.auto: gintsts=0480902c  gintmsk=d0bc3cc4
> [23984.272318] dwc2 dwc2.1.auto: ++OTG Interrupt gotgint=4 [b_peripheral]
> [23984.272321] dwc2 dwc2.1.auto:  ++OTG Interrupt: Session End 
> Detected++ (b_peripheral)
> [23984.272331] dwc2 dwc2.1.auto: complete: ep ffff880401a31b28 ep0, req 
> ffff8803e495ef00, -108 => ffffffffa00541da
> [23984.272336] dwc2 dwc2.1.auto: dwc2_hsotg_complete_setup: failed -108
> [23984.272346] dwc2 dwc2.1.auto: complete: ep ffff880401a30328 ep1out, 
> req ffff88040b6d7c80, -108 => ffffffffa008865c
> [23984.272435] dwc2 dwc2.1.auto: dwc2_hsotg_irq: 04809028 00801000 
> (d0bc3cc4) retry 8
> [23984.272437] dwc2 dwc2.1.auto: dwc2_hsotg_irq: USBRstDet
> [23984.272442] dwc2 dwc2.1.auto: dwc2_hsotg_irq: USBRst

here it is.

> [23984.272446] dwc2 dwc2.1.auto: GNPTXSTS=00040300
> [23984.272473] dwc2 dwc2.1.auto: dwc2_hsotg_ep_disable(ep ffff880401a30528)
> [23984.272478] dwc2 dwc2.1.auto: dwc2_hsotg_ep_disable: DxEPCTL=0x084a0200
> [23984.272485] dwc2 dwc2.1.auto: dwc2_hsotg_ep_disable(ep ffff880401a30328)
> [23984.272490] dwc2 dwc2.1.auto: dwc2_hsotg_ep_stop_xfr: stopping 
> transfer on ep1out
> [23984.272513] dwc2 dwc2.1.auto: dwc2_hsotg_ep_disable: DxEPCTL=0x08080200
> [23984.272540] dwc2 dwc2.1.auto: dwc2_hsotg_irq: 04008028 00000000 
> (d0bc3cc4) retry 8
>
> Connect
>
> [24010.664017] dwc2 dwc2.1.auto: gintsts=44008028  gintmsk=d0bc3cc4
> [24010.664023] dwc2 dwc2.1.auto: Session request interrupt - lx_state=0
> [24010.664035] dwc2 dwc2.1.auto: dwc2_hsotg_irq: 04008028 00000000 
> (d0bc3cc4) retry 8
>
> Run test
>
> First try to enumerate
>
> [24021.649528] dwc2 dwc2.1.auto: dwc2_hsotg_irq: 0400a028 00002000 
> (d0bc3cc4) retry 8
> [24021.649536] dwc2 dwc2.1.auto: EnumDone (DSTS=0x0043e902)
> [24021.649539] dwc2 dwc2.1.auto: new device is full-speed
> [24021.649618] dwc2 dwc2.1.auto: dwc2_hsotg_enqueue_setup: queueing 
> setup request
> [24021.649623] dwc2 dwc2.1.auto: ep0: req ffff8803e495ef00: 
> 8@ffff88040ad1d228, noi=0, zero=0, snok=0
> [24021.649631] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: 
> DxEPCTL=0x80028000, ep 0, dir out
> [24021.649636] dwc2 dwc2.1.auto: ureq->length:8 ureq->actual:0
> [24021.649640] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: 1@8/8, 0x00080008 
> => 0x00000b10
> [24021.649643] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: 
> 0x00000000d9858800 => 0x00000b14
> [24021.649645] dwc2 dwc2.1.auto: ep0 state:0
> [24021.649648] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: DxEPCTL=0x80028000
> [24021.649654] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: DXEPCTL=0x80028000
> [24021.649664] dwc2 dwc2.1.auto: EP0: DIEPCTL0=0x00008000, 
> DOEPCTL0=0x80028000
> [24021.849430] dwc2 dwc2.1.auto: dwc2_hsotg_irq: 04088028 00080000 
> (d0bc3cc4) retry 8
> [24021.849439] dwc2 dwc2.1.auto: dwc2_hsotg_irq: daint=00010000
> [24021.849452] dwc2 dwc2.1.auto: dwc2_hsotg_epint: ep0(out) 
> DxEPINT=0x00008009
> [24021.849455] dwc2 dwc2.1.auto: dwc2_hsotg_epint: Setup/Timeout
> [24021.849462] dwc2 dwc2.1.auto: complete: ep ffff880401a31b28 ep0, req 
> ffff8803e495ef00, 0 => ffffffffa00541da
> [24021.849468] dwc2 dwc2.1.auto: ctrl Type=80, Req=06, V=0100, I=0000, 
> L=0008
> [24021.849474] dwc2 dwc2.1.auto: ep0: req ffff88040d7c9b80: 
> 8@ffff8803e9af6000, noi=0, zero=0, snok=0
> [24021.849481] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: 
> DxEPCTL=0x00028000, ep 0, dir in
> [24021.849486] dwc2 dwc2.1.auto: ureq->length:8 ureq->actual:0
> [24021.849490] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: 1@8/8, 0x00080008 
> => 0x00000910
> [24021.849493] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: 
> 0x00000000d9859000 => 0x00000914
> [24021.849495] dwc2 dwc2.1.auto: ep0 state:1
> [24021.849498] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: DxEPCTL=0x84028000
> [24021.849504] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: DXEPCTL=0x80008000
> [24021.849560] dwc2 dwc2.1.auto: dwc2_hsotg_irq: 04048028 00040000 
> (d0bc3cc4) retry 8
> [24021.849567] dwc2 dwc2.1.auto: dwc2_hsotg_irq: daint=00000001
> [24021.849578] dwc2 dwc2.1.auto: dwc2_hsotg_epint: ep0(in) 
> DxEPINT=0x00000001
> [24021.849585] dwc2 dwc2.1.auto: dwc2_hsotg_epint: XferCompl: 
> DxEPCTL=0x00008000, DXEPTSIZ=00000000
> [24021.849590] dwc2 dwc2.1.auto: dwc2_hsotg_complete_in: adjusting size 
> done 0 => 8
> [24021.849593] dwc2 dwc2.1.auto: req->length:8 req->actual:8 req->zero:0
> [24021.849596] dwc2 dwc2.1.auto: Receiving zero-length packet on ep0
> [24021.849629] dwc2 dwc2.1.auto: dwc2_hsotg_irq: 04088028 00080000 
> (d0bc3cc4) retry 8
> [24021.849635] dwc2 dwc2.1.auto: dwc2_hsotg_irq: daint=00010000
> [24021.849647] dwc2 dwc2.1.auto: dwc2_hsotg_epint: ep0(out) 
> DxEPINT=0x00000001
> [24021.849654] dwc2 dwc2.1.auto: dwc2_hsotg_epint: XferCompl: 
> DxEPCTL=0x00028000, DXEPTSIZ=20000000
> [24021.849658] dwc2 dwc2.1.auto: zlp packet received
> [24021.849661] dwc2 dwc2.1.auto: complete: ep ffff880401a31b28 ep0, req 
> ffff88040d7c9b80, 0 => ffffffffa0076da7
> [24021.849665] dwc2 dwc2.1.auto: dwc2_hsotg_enqueue_setup: queueing 
> setup request
> [24021.849669] dwc2 dwc2.1.auto: ep0: req ffff8803e495ef00: 
> 8@ffff88040ad1d228, noi=0, zero=0, snok=0
> [24021.849674] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: 
> DxEPCTL=0x00028000, ep 0, dir out
> [24021.849679] dwc2 dwc2.1.auto: ureq->length:8 ureq->actual:0
> [24021.849682] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: 1@8/8, 0x00080008 
> => 0x00000b10
> [24021.849685] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: 
> 0x00000000d9859800 => 0x00000b14
> [24021.849687] dwc2 dwc2.1.auto: ep0 state:0
> [24021.849689] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: DxEPCTL=0x80028000
> [24021.849696] dwc2 dwc2.1.auto: dwc2_hsotg_start_req: DXEPCTL=0x80028000
>
>
> Second try to enumerate
>
> [24022.203534] dwc2 dwc2.1.auto: dwc2_hsotg_irq: 04008428 00000400 
> (d0bc3cc4) retry 8
> [24022.203539] dwc2 dwc2.1.auto: GINTSTS_ErlySusp
> [24022.206591] dwc2 dwc2.1.auto: gintsts=04008828  gintmsk=d0bc3cc4
> [24022.206595] dwc2 dwc2.1.auto: USB SUSPEND
> [24022.206602] dwc2 dwc2.1.auto: DSTS=0x426203
> [24022.206605] dwc2 dwc2.1.auto: DSTS.Suspend Status=1 HWCFG4.Power 
> Optimize=0
> [24022.206615] dwc2 dwc2.1.auto: dwc2_hsotg_irq: 04008028 00000000 
> (d0bc3cc4) retry 8
> [24022.432686] dwc2 dwc2.1.auto: dwc2_hsotg_irq: 04809028 00801000 
> (d0bc3cc4) retry 8
> [24022.432691] dwc2 dwc2.1.auto: dwc2_hsotg_irq: USBRstDet
> [24022.432695] dwc2 dwc2.1.auto: dwc2_hsotg_irq: USBRst

Here it is again.

If you implement reset correctly, then the problem will go away. Clear
DEVADDR from Reset, not Disconnect.

-- 
balbi