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

5 files changed, 108 insertions, 20 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 9e900f9..3febe54 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;
 }
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 8b9d669..0ab7da2 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1174,6 +1174,8 @@ void usb_disable_device(struct usb_device *dev, int skip_ep0)
 			put_device(&dev->actconfig->interface[i]->dev);
 			dev->actconfig->interface[i] = NULL;
 		}
+		usb_unlocked_disable_lpm(dev);
+		usb_disable_ltm(dev);
 		dev->actconfig = NULL;
 		if (dev->state == USB_STATE_CONFIGURED)
 			usb_set_device_state(dev, USB_STATE_ADDRESS);
@@ -1792,14 +1794,15 @@ free_interfaces:
 	 * installed, so that the xHCI driver can recalculate the U1/U2
 	 * timeouts.
 	 */
-	if (usb_disable_lpm(dev)) {
+	if (dev->actconfig && usb_disable_lpm(dev)) {
 		dev_err(&dev->dev, "%s Failed to disable LPM\n.", __func__);
 		mutex_unlock(hcd->bandwidth_mutex);
 		return -ENOMEM;
 	}
 	ret = usb_hcd_alloc_bandwidth(dev, cp, NULL, NULL);
 	if (ret < 0) {
-		usb_enable_lpm(dev);
+		if (dev->actconfig)
+			usb_enable_lpm(dev);
 		mutex_unlock(hcd->bandwidth_mutex);
 		usb_autosuspend_device(dev);
 		goto free_interfaces;
@@ -1819,7 +1822,7 @@ free_interfaces:
 	if (!cp) {
 		usb_set_device_state(dev, USB_STATE_ADDRESS);
 		usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
-		usb_enable_lpm(dev);
+		/* Leave LPM disabled while the device is unconfigured. */
 		mutex_unlock(hcd->bandwidth_mutex);
 		usb_autosuspend_device(dev);
 		goto free_interfaces;
@@ -1877,6 +1880,8 @@ free_interfaces:
 
 	/* Now that the interfaces are installed, re-enable LPM. */
 	usb_unlocked_enable_lpm(dev);
+	/* Enable LTM if it was turned off by usb_disable_device. */
+	usb_enable_ltm(dev);
 
 	/* Now that all the interfaces are set up, register them
 	 * to trigger binding of drivers to interfaces.  probe()
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 777f03c..682e825 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -253,6 +253,15 @@ show_removable(struct device *dev, struct device_attribute *attr, char *buf)
 }
 static DEVICE_ATTR(removable, S_IRUGO, show_removable, NULL);
 
+static ssize_t
+show_ltm_capable(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	if (usb_device_supports_ltm(to_usb_device(dev)))
+		return sprintf(buf, "%s\n", "yes");
+	return sprintf(buf, "%s\n", "no");
+}
+static DEVICE_ATTR(ltm_capable, S_IRUGO, show_ltm_capable, NULL);
+
 #ifdef	CONFIG_PM
 
 static ssize_t
@@ -649,6 +658,7 @@ static struct attribute *dev_attrs[] = {
 	&dev_attr_authorized.attr,
 	&dev_attr_remove.attr,
 	&dev_attr_removable.attr,
+	&dev_attr_ltm_capable.attr,
 	NULL,
 };
 static struct attribute_group dev_attr_grp = {
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 25d0c61..cd8fb44 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -396,6 +396,7 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent,
 	dev->dev.dma_mask = bus->controller->dma_mask;
 	set_dev_node(&dev->dev, dev_to_node(bus->controller));
 	dev->state = USB_STATE_ATTACHED;
+	dev->lpm_disable_count = 1;
 	atomic_set(&dev->urbnum, 0);
 
 	INIT_LIST_HEAD(&dev->ep0.urb_list);
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 7b01094..74bfc86 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -544,12 +544,18 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 		if (hcd->speed != HCD_USB3)
 			goto error;
 
+		/* Set the U1 and U2 exit latencies. */
 		memcpy(buf, &usb_bos_descriptor,
 				USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE);
 		temp = xhci_readl(xhci, &xhci->cap_regs->hcs_params3);
 		buf[12] = HCS_U1_LATENCY(temp);
 		put_unaligned_le16(HCS_U2_LATENCY(temp), &buf[13]);
 
+		/* Indicate whether the host has LTM support. */
+		temp = xhci_readl(xhci, &xhci->cap_regs->hcc_params);
+		if (HCC_LTC(temp))
+			buf[8] |= USB_LTM_SUPPORT;
+
 		spin_unlock_irqrestore(&xhci->lock, flags);
 		return USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE;
 	case GetPortStatus: