xhci: Return if xHCI doesn't support LPM

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@vger.kernel.org
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200624135949.22611-5-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Kai-Heng Feng 2020-06-24 16:59:48 +03:00 committed by Greg Kroah-Hartman
parent a24d5072e8
commit f0c472a6da

View file

@ -4391,6 +4391,9 @@ static int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd,
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(struct usb_hcd *hcd,
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