From bf5ce5bf3cc7136fd7fe5e8999a580bc93a9c8f6 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Sat, 14 Nov 2015 16:26:32 +0800 Subject: usb: core: lpm: fix usb3_hardware_lpm sysfs node Commit 655fe4effe0f ("usbcore: add sysfs support to xHCI usb3 hardware LPM") introduced usb3_hardware_lpm sysfs node. This doesn't show the correct status of USB3 U1 and U2 LPM status. This patch fixes this by replacing usb3_hardware_lpm with two nodes, usb3_hardware_lpm_u1 (for U1) and usb3_hardware_lpm_u2 (for U2), and recording the U1/U2 LPM status in right places. This patch should be back-ported to kernels as old as 4.3, that contains Commit 655fe4effe0f ("usbcore: add sysfs support to xHCI usb3 hardware LPM"). Cc: stable@vger.kernel.org Signed-off-by: Lu Baolu Signed-off-by: Greg Kroah-Hartman --- Documentation/usb/power-management.txt | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'Documentation/usb') diff --git a/Documentation/usb/power-management.txt b/Documentation/usb/power-management.txt index 4a15c90bc11d..0a94ffe17ab6 100644 --- a/Documentation/usb/power-management.txt +++ b/Documentation/usb/power-management.txt @@ -537,17 +537,18 @@ relevant attribute files are usb2_hardware_lpm and usb3_hardware_lpm. can write y/Y/1 or n/N/0 to the file to enable/disable USB2 hardware LPM manually. This is for test purpose mainly. - power/usb3_hardware_lpm + power/usb3_hardware_lpm_u1 + power/usb3_hardware_lpm_u2 When a USB 3.0 lpm-capable device is plugged in to a xHCI host which supports link PM, it will check if U1 and U2 exit latencies have been set in the BOS descriptor; if the check is is passed and the host supports USB3 hardware LPM, USB3 hardware LPM will be - enabled for the device and this file will be created. - The file holds a string value (enable or disable) - indicating whether or not USB3 hardware LPM is - enabled for the device. + enabled for the device and these files will be created. + The files hold a string value (enable or disable) + indicating whether or not USB3 hardware LPM U1 or U2 + is enabled for the device. USB Port Power Control ---------------------- -- cgit v1.2.3