@@ -4160,7 +4160,7 @@ static int usb_set_device_initiated_lpm(struct usb_device *udev,
"for unconfigured device.\n",
__func__, str_enable_disable(enable),
usb3_lpm_names[state]);
- return 0;
+ return -EINVAL;
}
if (enable) {
@@ -4341,13 +4341,6 @@ static void usb_enable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
return;
}
- /*
- * Enable device initiated U1/U2 with a SetFeature(U1/U2_ENABLE) request
- * if system exit latency is short enough and device is configured
- */
- if (usb_device_may_initiate_lpm(udev, state))
- usb_set_device_initiated_lpm(udev, state, true);
-
if (state == USB3_LPM_U1)
udev->usb3_lpm_u1_enabled = 1;
else if (state == USB3_LPM_U2)
@@ -4508,6 +4501,18 @@ void usb_enable_lpm(struct usb_device *udev)
if (port_dev->usb3_lpm_u2_permit)
usb_enable_link_state(hcd, udev, USB3_LPM_U2);
+
+ /*
+ * Enable device initiated U1/U2 with a SetFeature(U1/U2_ENABLE) request
+ * if system exit latency is short enough and device is configured
+ */
+ if (usb_device_may_initiate_lpm(udev, USB3_LPM_U1)) {
+ if (usb_set_device_initiated_lpm(udev, USB3_LPM_U1, true))
+ return;
+
+ if (usb_device_may_initiate_lpm(udev, USB3_LPM_U2))
+ usb_set_device_initiated_lpm(udev, USB3_LPM_U2, true);
+ }
}
EXPORT_SYMBOL_GPL(usb_enable_lpm);
Several usb requests are needed to allow a USB3 link to enter U1/U2 hardware link power management LPM states. Reorder these requests and send the more significant and likely to succeed first. This is similar to the change done for disabling LPM Enable LPM by first sending requests to the upstream hub of the device SetPortFeature(U1_TIMEOUT) SetPortFeature(U2_TIMEOUT) These are more likely to succeed due to the shorter path, and LPM can be considered enabled as link may go to U1/U2 LPM states after those. Send the requests to the device after this, they allow the device to initialte U1/U2 link transitions. Hub can already initiate U1/U2 SetFeature(U1_ENABLE) SetFeature(U2_ENABLE) Fail fast and bail out if a requests to the device fails. This changes device initated LPM policy a bit. Device is no longer able to initiate U2 if it failed or is not allowed to initiate U1. Enabling and disabling Link power management is done as part of hub work. Avoid trying to send additional USB requests to a device when there are known issues. It just causes hub work to block for even longer. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> --- drivers/usb/core/hub.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-)