RE: thunderbolt: Warning and 20 second delay in S4

From: "Mani, Rajmohan" <rajmohan.mani@intel.com>
To: Evan Green <evgreen@chromium.org>, Greg KH <gregkh@linuxfoundation.org>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>,
	"Fine, Gil" <gil.fine@intel.com>,
	"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
	Prashant Malani <pmalani@google.com>,
	LKML <linux-kernel@vger.kernel.org>
Subject: RE: thunderbolt: Warning and 20 second delay in S4
Date: Tue, 13 Jul 2021 00:16:25 +0000	[thread overview]
Message-ID: <DM6PR11MB39639EB194DF47AE6D7F77ECF6149@DM6PR11MB3963.namprd11.prod.outlook.com> (raw)
In-Reply-To: <CAE=gft6pax+OB-TDDUEUabmc8p3x-p7CC-9ihNbjRKq0MgdisA@mail.gmail.com>

Hi Evan,

> -----Original Message-----
> From: Evan Green <evgreen@chromium.org>
> Sent: Monday, July 12, 2021 4:46 PM
> To: Greg KH <gregkh@linuxfoundation.org>
> Cc: Mika Westerberg <mika.westerberg@linux.intel.com>; Fine, Gil
> <gil.fine@intel.com>; Mani, Rajmohan <rajmohan.mani@intel.com>; linux-
> usb@vger.kernel.org; Prashant Malani <pmalani@google.com>; LKML <linux-
> kernel@vger.kernel.org>
> Subject: Re: thunderbolt: Warning and 20 second delay in S4
> 
> On Fri, Jul 9, 2021 at 11:34 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Fri, Jul 09, 2021 at 02:31:35PM -0700, Evan Green wrote:
> > > Hi Mika et al,
> > >
> > > I'm experimenting with suspending to disk (hibernate) on a Tigerlake
> > > Chromebook running the chromeos-5.4 kernel. I don't have any USB4
> > > peripherals plugged in. I'm getting this warning, along with a 20
> > > second stall, both when going down for hibernate and coming back up.
> >
> > 5.4 is pretty old, especially for thunderbolt issues, can you try 5.13
> > please?
> 
> Good idea. On 5.13.0-next-20210709, I see the warning and delay even at boot
> when runtime pm kicks in. This should make for an easier repro at least:
> 
> [   18.832016] thunderbolt 0000:00:0d.2: 0: timeout reading config
> space 2 from 0x6
> [   18.840309] ------------[ cut here ]------------
> [   18.845466] thunderbolt 0000:00:0d.2: interrupt for RX ring 0 is
> already disabled
> [   18.853836] WARNING: CPU: 0 PID: 5 at drivers/thunderbolt/nhi.c:103
> ring_interrupt_active+0x1b7/0x1da
> ...
> [   18.977736] CPU: 0 PID: 5 Comm: kworker/0:0 Tainted: G     U
>     5.13.0-next-20210709 #18
> [   18.996804] Workqueue: pm pm_runtime_work
> [   19.001285] RIP: 0010:ring_interrupt_active+0x1b7/0x1da
> ...
> [   19.100302] Call Trace:
> [   19.103031]  tb_ring_stop+0x9d/0x17d
> [   19.107022]  tb_ctl_stop+0x33/0xa0
> [   19.110822]  tb_domain_runtime_suspend+0x35/0x3a
> [   19.115979]  nhi_runtime_suspend+0x1f/0x4c
> [   19.120557]  pci_pm_runtime_suspend+0x5a/0x173
> [   19.125533]  ? pci_pm_restore_noirq+0x73/0x73
> [   19.130411]  __rpm_callback+0x8a/0x10d
> [   19.134595]  rpm_callback+0x22/0x74
> [   19.138489]  ? pci_pm_restore_noirq+0x73/0x73
> [   19.143355]  rpm_suspend+0x21e/0x514
> [   19.147355]  pm_runtime_work+0x8a/0xa5
> [   19.151554]  process_one_work+0x1b7/0x368
> [   19.156027]  worker_thread+0x213/0x372
> [   19.160217]  kthread+0x147/0x15f
> [   19.163827]  ? pr_cont_work+0x58/0x58
> [   19.167928]  ? kthread_blkcg+0x31/0x31
> [   19.172113]  ret_from_fork+0x1f/0x30
> [   19.176105] ---[ end trace 438b7f20f6b4049d ]---

I used to see these timeout errors, when there was a control
read/write issued to the thunderbolt/usb4 device, after the
thunderbolt driver is suspended.
Can you share the steps to reproduce this S4 issue in a Chrome device?

Thanks
Raj