This is a note to let you know that I've just added the patch titled
xhci: Return if xHCI doesn't support LPM
to the 5.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xhci-return-if-xhci-doesn-t-support-lpm.patch
and it can be found in the queue-5.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f0c472a6da51f9fac15e80fe2fd9c83b68754cff Mon Sep 17 00:00:00 2001
From: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
Date: Wed, 24 Jun 2020 16:59:48 +0300
Subject: xhci: Return if xHCI doesn't support LPM
From: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
commit f0c472a6da51f9fac15e80fe2fd9c83b68754cff upstream.
Just return if xHCI is quirked to disable LPM. We can save some time
from reading registers and doing spinlocks.
Add stable tag as we want this patch together with the next one,
"Poll for U0 after disabling USB2 LPM" which fixes a suspend issue
for some USB2 LPM devices
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200624135949.22611-5-mathias.nyman@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4391,6 +4391,9 @@ static int xhci_set_usb2_hardware_lpm(st
int hird, exit_latency;
int ret;
+ if (xhci->quirks & XHCI_HW_LPM_DISABLE)
+ return -EPERM;
+
if (hcd->speed >= HCD_USB3 || !xhci->hw_lpm_support ||
!udev->lpm_capable)
return -EPERM;
@@ -4413,7 +4416,7 @@ static int xhci_set_usb2_hardware_lpm(st
xhci_dbg(xhci, "%s port %d USB2 hardware LPM\n",
enable ? "enable" : "disable", port_num + 1);
- if (enable && !(xhci->quirks & XHCI_HW_LPM_DISABLE)) {
+ if (enable) {
/* Host supports BESL timeout instead of HIRD */
if (udev->usb2_hw_lpm_besl_capable) {
/* if device doesn't have a preferred BESL value use a
Patches currently in stable-queue which might be from kai.heng.feng@xxxxxxxxxxxxx are
queue-5.7/xhci-return-if-xhci-doesn-t-support-lpm.patch
queue-5.7/xhci-poll-for-u0-after-disabling-usb2-lpm.patch
