Merge tag 'for-usb-next-2012-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/sarah/xhci into usb-next

USB: Link PM fixes and Latency Tolerance Messaging

Hi Greg,

Here's four bug fix patches for Link PM (LPM), which are marked for
3.5-stable.  There's also three patches that turn on Latency Tolerance
Messaging (LTM) for xHCI host controllers and USB 3.0 devices that support
this low power feature.

Please queue for 3.6.

Sarah Sharp

1 files changed, 83 insertions, 17 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 9e900f9a2ef7..3febe54883bd 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2614,6 +2614,50 @@ static int check_port_resume_type(struct usb_device *udev,
         return status;
 }
 
+int usb_disable_ltm(struct usb_device *udev)
+{
+        struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+
+        /* Check if the roothub and device supports LTM. */
+        if (!usb_device_supports_ltm(hcd->self.root_hub) ||
+                        !usb_device_supports_ltm(udev))
+                return 0;
+
+        /* Clear Feature LTM Enable can only be sent if the device is
+         * configured.
+         */
+        if (!udev->actconfig)
+                return 0;
+
+        return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+                        USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
+                        USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
+                        USB_CTRL_SET_TIMEOUT);
+}
+EXPORT_SYMBOL_GPL(usb_disable_ltm);
+
+void usb_enable_ltm(struct usb_device *udev)
+{
+        struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+
+        /* Check if the roothub and device supports LTM. */
+        if (!usb_device_supports_ltm(hcd->self.root_hub) ||
+                        !usb_device_supports_ltm(udev))
+                return;
+
+        /* Set Feature LTM Enable can only be sent if the device is
+         * configured.
+         */
+        if (!udev->actconfig)
+                return;
+
+        usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+                        USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
+                        USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
+                        USB_CTRL_SET_TIMEOUT);
+}
+EXPORT_SYMBOL_GPL(usb_enable_ltm);
+
 #ifdef  CONFIG_USB_SUSPEND
 
 /*
@@ -2709,6 +2753,11 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
         if (udev->usb2_hw_lpm_enabled == 1)
                 usb_set_usb2_hardware_lpm(udev, 0);
 
+        if (usb_disable_ltm(udev)) {
+                dev_err(&udev->dev, "%s Failed to disable LTM before suspend\n.",
+                                __func__);
+                return -ENOMEM;
+        }
         if (usb_unlocked_disable_lpm(udev)) {
                 dev_err(&udev->dev, "%s Failed to disable LPM before suspend\n.",
                                 __func__);
@@ -2738,7 +2787,8 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
                 if (udev->usb2_hw_lpm_capable == 1)
                         usb_set_usb2_hardware_lpm(udev, 1);
 
-                /* Try to enable USB3 LPM again */
+                /* Try to enable USB3 LTM and LPM again */
+                usb_enable_ltm(udev);
                 usb_unlocked_enable_lpm(udev);
 
                 /* System sleep transitions should never fail */
@@ -2939,7 +2989,8 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
                 if (udev->usb2_hw_lpm_capable == 1)
                         usb_set_usb2_hardware_lpm(udev, 1);
 
-                /* Try to enable USB3 LPM */
+                /* Try to enable USB3 LTM and LPM */
+                usb_enable_ltm(udev);
                 usb_unlocked_enable_lpm(udev);
         }
 
@@ -3492,6 +3543,15 @@ EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
 
 void usb_unlocked_enable_lpm(struct usb_device *udev) { }
 EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
+
+int usb_disable_ltm(struct usb_device *udev)
+{
+        return 0;
+}
+EXPORT_SYMBOL_GPL(usb_disable_ltm);
+
+void usb_enable_ltm(struct usb_device *udev) { }
+EXPORT_SYMBOL_GPL(usb_enable_ltm);
 #endif
 
 
@@ -4675,6 +4735,23 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
         }
         parent_hub = hdev_to_hub(parent_hdev);
 
+        /* Disable LPM and LTM while we reset the device and reinstall the alt
+         * settings.  Device-initiated LPM settings, and system exit latency
+         * settings are cleared when the device is reset, so we have to set
+         * them up again.
+         */
+        ret = usb_unlocked_disable_lpm(udev);
+        if (ret) {
+                dev_err(&udev->dev, "%s Failed to disable LPM\n.", __func__);
+                goto re_enumerate;
+        }
+        ret = usb_disable_ltm(udev);
+        if (ret) {
+                dev_err(&udev->dev, "%s Failed to disable LTM\n.",
+                                __func__);
+                goto re_enumerate;
+        }
+
         set_bit(port1, parent_hub->busy_bits);
         for (i = 0; i < SET_CONFIG_TRIES; ++i) {
 
@@ -4702,22 +4779,11 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
                 goto done;
 
         mutex_lock(hcd->bandwidth_mutex);
-        /* Disable LPM while we reset the device and reinstall the alt settings.
-         * Device-initiated LPM settings, and system exit latency settings are
-         * cleared when the device is reset, so we have to set them up again.
-         */
-        ret = usb_disable_lpm(udev);
-        if (ret) {
-                dev_err(&udev->dev, "%s Failed to disable LPM\n.", __func__);
-                mutex_unlock(hcd->bandwidth_mutex);
-                goto done;
-        }
         ret = usb_hcd_alloc_bandwidth(udev, udev->actconfig, NULL, NULL);
         if (ret < 0) {
                 dev_warn(&udev->dev,
                                 "Busted HC?  Not enough HCD resources for "
                                 "old configuration.\n");
-                usb_enable_lpm(udev);
                 mutex_unlock(hcd->bandwidth_mutex);
                 goto re_enumerate;
         }
@@ -4729,7 +4795,6 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
                 dev_err(&udev->dev,
                         "can't restore configuration #%d (error=%d)\n",
                         udev->actconfig->desc.bConfigurationValue, ret);
-                usb_enable_lpm(udev);
                 mutex_unlock(hcd->bandwidth_mutex);
                 goto re_enumerate;
         }
@@ -4768,17 +4833,18 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
                                 desc->bInterfaceNumber,
                                 desc->bAlternateSetting,
                                 ret);
-                        usb_unlocked_enable_lpm(udev);
                         goto re_enumerate;
                 }
         }
 
-        /* Now that the alt settings are re-installed, enable LPM. */
-        usb_unlocked_enable_lpm(udev);
 done:
+        /* Now that the alt settings are re-installed, enable LTM and LPM. */
+        usb_unlocked_enable_lpm(udev);
+        usb_enable_ltm(udev);
         return 0;
  
 re_enumerate:
+        /* LPM state doesn't matter when we're about to destroy the device. */
         hub_port_logical_disconnect(parent_hub, port1);
         return -ENODEV;
 }