Re: dwc3 gadget breaks on system suspend/resume

Felipe Balbi
2017-01-27T15:47:22Z

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Hi,

(hmm, I didn't receive your reply in my intel inbox, only
gmail. Odd. Replying to myself here, but it should be on your reply,
rater).

Felipe Balbi <balbi-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> writes:
>> The previous commit c499ff71ff2a281366c6ec7a904c547d806cbcd1 is fine.
>
> okay. Then let's try to figure out what's going on. A diff of regdump
> before and after suspend/resume might start to give some clue about
> what's going on. DWC3 tracepoints should help too. Care to get those?
> BTW, is this dwc3 as host or peripheral?

You don't have any endpoints enabled:

-DALEPENA = 0x0000000f
+DALEPENA = 0x00000000

Your traces are peculiar:

> irq/451-dwc3-2082 [000] d... 108.215104: dwc3_gadget: Disabling ep1in-bulk

okay, let's disable ep1in-bulk

> irq/451-dwc3-2082 [000] d... 108.215106: dwc3_gadget_ep_cmd: ep1in-bulk: cmd 'End Transfer' [198920] params 00000000 00000000 00000000
> irq/451-dwc3-2082 [000] d... 108.215109: dwc3_readl: addr fa89c200 value 00002500
> irq/451-dwc3-2082 [000] d... 108.215114: dwc3_writel: addr fa89c838 value 00000000
> irq/451-dwc3-2082 [000] d... 108.215116: dwc3_writel: addr fa89c834 value 00000000
> irq/451-dwc3-2082 [000] d... 108.215118: dwc3_writel: addr fa89c830 value 00000000
> irq/451-dwc3-2082 [000] d... 108.215120: dwc3_writel: addr fa89c83c value 00030d08
> irq/451-dwc3-2082 [000] d... 108.215123: dwc3_readl: addr fa89c83c value 00031908
> irq/451-dwc3-2082 [000] d... 108.215125: dwc3_gadget: Command Complete --> 1
> irq/451-dwc3-2082 [000] d... 108.215127: dwc3_gadget: (null): no resource available
> irq/451-dwc3-2082 [000] d... 108.495119: dwc3_gadget_giveback: ep1in-bulk: req ed5cae80 length 0/4096 zsI ==> -108
> irq/451-dwc3-2082 [000] d... 108.495123: dwc3_free_request: ep1in-bulk: req ed5cae80 length 0/4096 zsI ==> -108
> irq/451-dwc3-2082 [000] d... 108.495127: dwc3_readl: addr fa89c720 value 00000000

read DALEPENA, already 0x00. How was ep1in-bulk even enabled???

> irq/451-dwc3-2082 [000] d... 108.495130: dwc3_writel: addr fa89c720 value 00000000

clear bit for ep1in-bulk and write back the 0x00 you read. What gives??
Why is DALEPENA already zero here????

> irq/451-dwc3-2082 [000] d... 108.495135: dwc3_gadget: Disabling ep1out-bulk
> irq/451-dwc3-2082 [000] d... 108.495137: dwc3_gadget_ep_cmd: ep1out-bulk: cmd 'End Transfer' [133384] params 00000000 00000000 00000000
> irq/451-dwc3-2082 [000] d... 108.495139: dwc3_readl: addr fa89c200 value 00002500
> irq/451-dwc3-2082 [000] d... 108.495143: dwc3_writel: addr fa89c828 value 00000000
> irq/451-dwc3-2082 [000] d... 108.495145: dwc3_writel: addr fa89c824 value 00000000
> irq/451-dwc3-2082 [000] d... 108.495146: dwc3_writel: addr fa89c820 value 00000000
> irq/451-dwc3-2082 [000] d... 108.495148: dwc3_writel: addr fa89c82c value 00020d08
> irq/451-dwc3-2082 [000] d... 108.495151: dwc3_readl: addr fa89c82c value 00021908
> irq/451-dwc3-2082 [000] d... 108.495153: dwc3_gadget: Command Complete --> 1
> irq/451-dwc3-2082 [000] d... 108.495154: dwc3_gadget: (null): no resource available
> irq/451-dwc3-2082 [000] d... 108.495258: dwc3_gadget_giveback: ep1out-bulk: req ed76d080 length 0/4096 zsI ==> -108
> irq/451-dwc3-2082 [000] d... 108.495261: dwc3_free_request: ep1out-bulk: req ed76d080 length 0/4096 zsI ==> -108
> irq/451-dwc3-2082 [000] d... 108.495264: dwc3_readl: addr fa89c720 value 00000000
> irq/451-dwc3-2082 [000] d... 108.495266: dwc3_writel: addr fa89c720 value 00000000

same thing for ep1out-bulk. When you get a "Disabling epxxxx" message,
we not only clear DALEPENA (which shouldn't be zero, btw!), but we
also clear dep->flags unconditionally. Here's a blame of v4.7 for that
function:

72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 669) static int __dwc3_gadget_ep_disable(struct dwc3_ep *dep)
72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 670) {
72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 671) struct dwc3 *dwc = dep->dwc;
72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 672) u32 reg;
72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 673)
7eaeac5c0e449 (Felipe Balbi 2015-07-20 14:46:15 -0500 674) dwc3_trace(trace_dwc3_gadget, "Disabling %s", dep->name);
7eaeac5c0e449 (Felipe Balbi 2015-07-20 14:46:15 -0500 675)
624407f96f134 (Sebastian Andrzej Siewior 2011-08-29 13:56:37 +0200 676) dwc3_remove_requests(dwc, dep);
72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 677)
687ef9817df7e (Felipe Balbi 2014-04-16 10:30:33 -0500 678) /* make sure HW endpoint isn't stalled */
687ef9817df7e (Felipe Balbi 2014-04-16 10:30:33 -0500 679) if (dep->flags & DWC3_EP_STALL)
7a60855972f0d (Felipe Balbi 2014-09-24 14:19:52 -0500 680) __dwc3_gadget_ep_set_halt(dep, 0, false);
687ef9817df7e (Felipe Balbi 2014-04-16 10:30:33 -0500 681)
72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 682) reg = dwc3_readl(dwc->regs, DWC3_DALEPENA);
72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 683) reg &= ~DWC3_DALEPENA_EP(dep->number);
72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 684) dwc3_writel(dwc->regs, DWC3_DALEPENA, reg);
72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 685)
879631aa658be (Felipe Balbi 2011-09-30 10:58:47 +0300 686) dep->stream_capable = false;
f9c56cdd3905c (Ido Shayevitz 2012-02-08 13:56:48 +0200 687) dep->endpoint.desc = NULL;
c90bfaece97c1 (Felipe Balbi 2011-11-29 13:11:21 +0200 688) dep->comp_desc = NULL;
72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 689) dep->type = 0;
879631aa658be (Felipe Balbi 2011-09-30 10:58:47 +0300 690) dep->flags = 0;
72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 691)
aa7399744dd02 (Felipe Balbi 2015-07-20 14:48:13 -0500 692) snprintf(dep->name, sizeof(dep->name), "ep%d%s",
aa7399744dd02 (Felipe Balbi 2015-07-20 14:48:13 -0500 693) dep->number >> 1,
aa7399744dd02 (Felipe Balbi 2015-07-20 14:48:13 -0500 694) (dep->number & 1) ? "in" : "out");
aa7399744dd02 (Felipe Balbi 2015-07-20 14:48:13 -0500 695)
72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 696) return 0;
72246da40f371 (Felipe Balbi 2011-08-19 18:10:58 +0300 697) }

let's keep going, there's more...

> irq/451-dwc3-2082 [000] d... 108.495280: dwc3_readl: addr fa89c704 value 80000000
> irq/451-dwc3-2082 [000] d... 108.495283: dwc3_writel: addr fa89c704 value 80000000
> irq/451-dwc3-2082 [000] d... 108.495287: dwc3_readl: addr fa89c700 value 004c098c
> irq/451-dwc3-2082 [000] d... 108.495290: dwc3_writel: addr fa89c700 value 004c0804
> irq/451-dwc3-2082 [000] d... 108.495292: dwc3_writel: addr fa89c40c value 00000004
> irq/451-dwc3-2082 [000] d... 108.495295: dwc3_readl: addr fa89c408 value 80000100
> irq/451-dwc3-2082 [000] d... 108.495297: dwc3_writel: addr fa89c408 value 00000100
> irq/451-dwc3-2082 [000] d.H. 108.495342: dwc3_readl: addr fa89c40c value 00000010
> irq/451-dwc3-2082 [000] d.H. 108.495347: dwc3_readl: addr fa89c408 value 00000100
> irq/451-dwc3-2082 [000] d.H. 108.495349: dwc3_writel: addr fa89c408 value 80000100
> irq/451-dwc3-2082 [000] d... 108.495374: dwc3_event: event 080311c6
> irq/451-dwc3-2082 [000] d... 108.495378: dwc3_writel: addr fa89c40c value 00000004
> irq/451-dwc3-2082 [000] d... 108.495381: dwc3_event: event 00000201
> irq/451-dwc3-2082 [000] d... 108.495383: dwc3_readl: addr fa89c70c value 00006838
> irq/451-dwc3-2082 [000] d... 108.495385: dwc3_readl: addr fa89c700 value 004c0804
> irq/451-dwc3-2082 [000] d... 108.495388: dwc3_writel: addr fa89c700 value 004c0804
> irq/451-dwc3-2082 [000] d... 108.495390: dwc3_readl: addr fa89c704 value 80000000
> irq/451-dwc3-2082 [000] d... 108.495392: dwc3_writel: addr fa89c704 value 8c000000
> irq/451-dwc3-2082 [000] d... 108.495394: dwc3_gadget: Enabling ep0out

... Enabling ep0out.

> irq/451-dwc3-2082 [000] d... 108.495397: dwc3_gadget_ep_cmd: ep0out: cmd 'Set Endpoint Configuration' [1] params 80000200 00000500 00000000
> irq/451-dwc3-2082 [000] d... 108.495399: dwc3_readl: addr fa89c200 value 00002500
> irq/451-dwc3-2082 [000] d... 108.495401: dwc3_writel: addr fa89c808 value 80000200
> irq/451-dwc3-2082 [000] d... 108.495403: dwc3_writel: addr fa89c804 value 00000500
> irq/451-dwc3-2082 [000] d... 108.495405: dwc3_writel: addr fa89c800 value 00000000
> irq/451-dwc3-2082 [000] d... 108.495406: dwc3_writel: addr fa89c80c value 00000401
> irq/451-dwc3-2082 [000] d... 108.495409: dwc3_readl: addr fa89c80c value 00000001
> irq/451-dwc3-2082 [000] d... 108.495411: dwc3_gadget: Command Complete --> 0

no writes to DALEPENA!

> irq/451-dwc3-2082 [000] d... 108.495413: dwc3_gadget: Enabling ep0in
> irq/451-dwc3-2082 [000] d... 108.495415: dwc3_gadget_ep_cmd: ep0in: cmd 'Set Endpoint Configuration' [1] params 80000200 02000500 00000000
> irq/451-dwc3-2082 [000] d... 108.495416: dwc3_readl: addr fa89c200 value 00002500
> irq/451-dwc3-2082 [000] d... 108.495419: dwc3_writel: addr fa89c818 value 80000200
> irq/451-dwc3-2082 [000] d... 108.495420: dwc3_writel: addr fa89c814 value 02000500
> irq/451-dwc3-2082 [000] d... 108.495423: dwc3_writel: addr fa89c810 value 00000000
> irq/451-dwc3-2082 [000] d... 108.495425: dwc3_writel: addr fa89c81c value 00000401
> irq/451-dwc3-2082 [000] d... 108.495428: dwc3_readl: addr fa89c81c value 00000001
> irq/451-dwc3-2082 [000] d... 108.495429: dwc3_gadget: Command Complete --> 0

nor here! however we disabled ep0/1 on gadget_suspend:

0b0231aa246cb (Felipe Balbi 2014-10-07 10:19:23 -0500 2936) int dwc3_gadget_suspend(struct dwc3 *dwc)
7415f17c9560c (Felipe Balbi 2012-04-30 14:56:33 +0300 2937) {
9772b47a4c291 (Roger Quadros 2016-04-12 11:33:29 +0300 2938) if (!dwc->gadget_driver)
9772b47a4c291 (Roger Quadros 2016-04-12 11:33:29 +0300 2939) return 0;
9772b47a4c291 (Roger Quadros 2016-04-12 11:33:29 +0300 2940)
7b2a0368bbc9b (Felipe Balbi 2013-12-19 13:43:19 -0600 2941) if (dwc->pullups_connected) {
7415f17c9560c (Felipe Balbi 2012-04-30 14:56:33 +0300 2942) dwc3_gadget_disable_irq(dwc);
7b2a0368bbc9b (Felipe Balbi 2013-12-19 13:43:19 -0600 2943) dwc3_gadget_run_stop(dwc, true, true);
7b2a0368bbc9b (Felipe Balbi 2013-12-19 13:43:19 -0600 2944) }
7415f17c9560c (Felipe Balbi 2012-04-30 14:56:33 +0300 2945)
7415f17c9560c (Felipe Balbi 2012-04-30 14:56:33 +0300 2946) __dwc3_gadget_ep_disable(dwc->eps[0]);
7415f17c9560c (Felipe Balbi 2012-04-30 14:56:33 +0300 2947) __dwc3_gadget_ep_disable(dwc->eps[1]);
7415f17c9560c (Felipe Balbi 2012-04-30 14:56:33 +0300 2948)
7415f17c9560c (Felipe Balbi 2012-04-30 14:56:33 +0300 2949) dwc->dcfg = dwc3_readl(dwc->regs, DWC3_DCFG);
7415f17c9560c (Felipe Balbi 2012-04-30 14:56:33 +0300 2950)
7415f17c9560c (Felipe Balbi 2012-04-30 14:56:33 +0300 2951) return 0;
7415f17c9560c (Felipe Balbi 2012-04-30 14:56:33 +0300 2952) }

--
balbi

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