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Subject: Re: [PATCH v3] xhci: Prevent runtime suspend on Etron EJ168
From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
In-Reply-To: <8d913b15-a7e4-5e35-a137-355d222ccf1f@linux.intel.com>
Date:   Tue, 29 Sep 2020 15:39:23 +0800
Cc:     Mathias Nyman <mathias.nyman@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "open list:USB XHCI DRIVER" <linux-usb@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
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Message-Id: <E2501192-3B1E-4887-92CB-AD6ECDED65F9@canonical.com>
References: <20200504171642.26947-1-kai.heng.feng@canonical.com>
 <0F26EE78-D4F4-4CCB-892B-999E203BF515@canonical.com>
 <14291E1B-6580-4C69-9EF8-3B30BC78B8D0@canonical.com>
 <8d913b15-a7e4-5e35-a137-355d222ccf1f@linux.intel.com>
To:     Mathias Nyman <mathias.nyman@linux.intel.com>
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> On Sep 29, 2020, at 05:42, Mathias Nyman <mathias.nyman@linux.intel.com> wrote:
> 
> On 28.9.2020 12.10, Kai-Heng Feng wrote:
>> 
>> 
>>> On Jun 8, 2020, at 11:56, Kai-Heng Feng <kai.heng.feng@canonical.com> wrote:
>>> 
>>> 
>>> 
>>>> On May 5, 2020, at 01:16, Kai-Heng Feng <kai.heng.feng@canonical.com> wrote:
>>>> 
>>>> Etron EJ168 USB 3.0 Host Controller stops working after S3, if it was
>>>> runtime suspended previously:
>>>> [  370.080359] pci 0000:02:00.0: can't change power state from D3cold to D0 (config space inaccessible)
>>>> [  370.080477] xhci_hcd 0000:04:00.0: can't change power state from D3cold to D0 (config space inaccessible)
>>>> [  370.080532] pcieport 0000:00:1c.0: DPC: containment event, status:0x1f05 source:0x0200
>>>> [  370.080533] pcieport 0000:00:1c.0: DPC: ERR_FATAL detected
>>>> [  370.080536] xhci_hcd 0000:04:00.0: can't change power state from D3hot to D0 (config space inaccessible)
>>>> [  370.080552] xhci_hcd 0000:04:00.0: AER: can't recover (no error_detected callback)
>>>> [  370.080566] usb usb3: root hub lost power or was reset
>>>> [  370.080566] usb usb4: root hub lost power or was reset
>>>> [  370.080572] xhci_hcd 0000:04:00.0: Host halt failed, -19
>>>> [  370.080574] xhci_hcd 0000:04:00.0: Host not accessible, reset failed.
>>>> [  370.080575] xhci_hcd 0000:04:00.0: PCI post-resume error -19!
>>>> [  370.080586] xhci_hcd 0000:04:00.0: HC died; cleaning up
>>>> 
>>>> This can be fixed by not runtime suspend the controller at all.
>>>> 
>>>> So disable runtime suspend for EJ168 xHCI device.
>>>> 
>>>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
>>> 
>>> A gentle ping...
>> 
>> Another gentle ping...
> 
> Thanks, somehow I didn't notice this earlier.
> 
> Was the rootcause ever investigated?
> Preventing runtime suspend looks like a quick fix to get rid of the issue, but 
> possibly just hides some other underlying power management problem

I tried different angles but didn't find any useful solution.

Eventually I found out that the device stays at D0 under Windows, so this is the approach I take.

Kai-Heng

> 
> -Mathias