Commit f0c472a6 authored Jun 24, 2020 by Kai-Heng Feng Committed by Greg Kroah-Hartman Jun 24, 2020

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>

parent a24d5072

drivers/usb/host/xhci.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -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

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