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

From: Mathias Nyman
Date: Thu Dec 13 2018 - 07:20:26 EST

On 13.12.2018 09:36, Greg Kroah-Hartman wrote:
On Wed, Dec 12, 2018 at 11:53:34PM +0100, Thomas Zeitlhofer wrote:

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


From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>

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:

close lid => system hibernates
open lid => system stays off
press power button => system boots and resumes

# 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) &&
bus_state->bus_suspended = 0;
spin_unlock_irqrestore(&xhci->lock, flags);
xhci_dbg(xhci, "Bus suspend bailout, port in polling\n");