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 <baolu.lu@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index bdeadc1..59f998e 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3875,17 +3875,30 @@
return;
}
- if (usb_set_lpm_timeout(udev, state, timeout))
+ if (usb_set_lpm_timeout(udev, state, timeout)) {
/* If we can't set the parent hub U1/U2 timeout,
* device-initiated LPM won't be allowed either, so let the xHCI
* host know that this link state won't be enabled.
*/
hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state);
+ } else {
+ /* Only a configured device will accept the Set Feature
+ * U1/U2_ENABLE
+ */
+ if (udev->actconfig)
+ usb_set_device_initiated_lpm(udev, state, true);
- /* Only a configured device will accept the Set Feature U1/U2_ENABLE */
- else if (udev->actconfig)
- usb_set_device_initiated_lpm(udev, state, true);
-
+ /* As soon as usb_set_lpm_timeout(timeout) returns 0, the
+ * hub-initiated LPM is enabled. Thus, LPM is enabled no
+ * matter the result of usb_set_device_initiated_lpm().
+ * The only difference is whether device is able to initiate
+ * LPM.
+ */
+ if (state == USB3_LPM_U1)
+ udev->usb3_lpm_u1_enabled = 1;
+ else if (state == USB3_LPM_U2)
+ udev->usb3_lpm_u2_enabled = 1;
+ }
}
/*
@@ -3925,6 +3938,18 @@
dev_warn(&udev->dev, "Could not disable xHCI %s timeout, "
"bus schedule bandwidth may be impacted.\n",
usb3_lpm_names[state]);
+
+ /* As soon as usb_set_lpm_timeout(0) return 0, hub initiated LPM
+ * is disabled. Hub will disallows link to enter U1/U2 as well,
+ * even device is initiating LPM. Hence LPM is disabled if hub LPM
+ * timeout set to 0, no matter device-initiated LPM is disabled or
+ * not.
+ */
+ if (state == USB3_LPM_U1)
+ udev->usb3_lpm_u1_enabled = 0;
+ else if (state == USB3_LPM_U2)
+ udev->usb3_lpm_u2_enabled = 0;
+
return 0;
}
@@ -3959,8 +3984,6 @@
if (usb_disable_link_state(hcd, udev, USB3_LPM_U2))
goto enable_lpm;
- udev->usb3_lpm_enabled = 0;
-
return 0;
enable_lpm:
@@ -4018,8 +4041,6 @@
usb_enable_link_state(hcd, udev, USB3_LPM_U1);
usb_enable_link_state(hcd, udev, USB3_LPM_U2);
-
- udev->usb3_lpm_enabled = 1;
}
EXPORT_SYMBOL_GPL(usb_enable_lpm);