linux-kernel - Re: [PATCH 4.19 014/110] usb: xhci: Prevent bus suspend if a port connect change or polling state is detected

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Message-ID: <06384740-496f-ce37-34bc-3e55fd9ed538@linux.intel.com>
Date:   Thu, 13 Dec 2018 14:24:14 +0200
From:   Mathias Nyman <mathias.nyman@...ux.intel.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Thomas Zeitlhofer <thomas.zeitlhofer@...it.at>
Cc:     linux-kernel@...r.kernel.org, stable@...r.kernel.org,
        linux-usb@...r.kernel.org
Subject: Re: [PATCH 4.19 014/110] usb: xhci: Prevent bus suspend if a port
 connect change or polling state is detected

On 13.12.2018 09:36, Greg Kroah-Hartman wrote:
> On Wed, Dec 12, 2018 at 11:53:34PM +0100, Thomas Zeitlhofer wrote:
>> Hello,
>>
>> On Thu, Nov 29, 2018 at 03:11:45PM +0100, Greg Kroah-Hartman wrote:
>>> 4.19-stable review patch.  If anyone has any objections, please let me
>>> know.
>>>
>>> ------------------
>>>
>>> From: Mathias Nyman <mathias.nyman@...ux.intel.com>
>>>
>>> commit 2f31a67f01a8beb22cae754c53522cb61a005750 upstream.
>> [...]
>>
>> on a current Thinkpad X1 Yoga, this breaks resume from hibernate such
>> that opening the lid has (in the regular use case, see below) no effect
>> any more:
>>
>> The system is configured to hibernate when the lid is closed. So, the
>> expected behavior, which is restored by reverting this patch, is:
>>
>> 	close lid => system hibernates
>> 	open lid => system resumes
>>
>> With this patch, the following two cases are observed:
>>
>> 	1)
>> 		close lid => system hibernates
>> 		open lid => system stays off
>> 		press power button => system boots and resumes
>>
>> 	2)
>> 		# systemctl hibernate => system hibernates
>> 		close lid
>> 		open lid => system resumes
>>
> 
> So this is a problem in Linus's tree?  If so, let's work to get this
> fixed there first.
> 
> If not, then we have other issues :)
> 

That patch incorrectly reacts to USB2 polling states as well,
which could cause issues like this.

Does applying the below code help?

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 94aca1b..01b5818 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -1507,7 +1507,8 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
                 portsc_buf[port_index] = 0;
  
                 /* Bail out if a USB3 port has a new device in link training */
-               if ((t1 & PORT_PLS_MASK) == XDEV_POLLING) {
+               if ((hcd->speed >= HCD_USB3) &&
+                   (t1 & PORT_PLS_MASK) == XDEV_POLLING) {
                         bus_state->bus_suspended = 0;
                         spin_unlock_irqrestore(&xhci->lock, flags);
                         xhci_dbg(xhci, "Bus suspend bailout, port in polling\n");