usb: core: lpm: fix usb3_hardware_lpm sysfs node (bf5ce5bf) · Commits · 戴 / test

Documentation/ABI/testing/sysfs-bus-usb

+9 −7

Original line number	Diff line number	Diff line
		@@ -134,19 +134,21 @@ Description:
		enabled for the device. Developer can write y/Y/1 or n/N/0 to
		the file to enable/disable the feature.

		What: /sys/bus/usb/devices/.../power/usb3_hardware_lpm
		Date: June 2015
		What: /sys/bus/usb/devices/.../power/usb3_hardware_lpm_u1
		/sys/bus/usb/devices/.../power/usb3_hardware_lpm_u2
		Date: November 2015
		Contact: Kevin Strasser <kevin.strasser@linux.intel.com>
		Lu Baolu <baolu.lu@linux.intel.com>
		Description:
		If CONFIG_PM is set and 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,
		the check is passed and the host supports USB3 hardware LPM,
		USB3 hardware LPM will be enabled for the device and the USB
		device directory will contain a file named
		power/usb3_hardware_lpm. The file holds a string value (enable
		or disable) indicating whether or not USB3 hardware LPM is
		enabled for the device.
		device directory will contain two files named
		power/usb3_hardware_lpm_u1 and power/usb3_hardware_lpm_u2. These
		files hold a string value (enable or disable) indicating whether
		or not USB3 hardware LPM U1 or U2 is enabled for the device.

		What: /sys/bus/usb/devices/.../removable
		Date: February 2012

Documentation/usb/power-management.txt

+6 −5

Original line number	Diff line number	Diff line
		@@ -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
		----------------------

drivers/usb/core/hub.c

+30 −9

Original line number	Diff line number	Diff line
		@@ -3875,17 +3875,30 @@ static void usb_enable_link_state(struct usb_hcd hcd, struct usb_device udev,
		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);

		/* Only a configured device will accept the Set Feature U1/U2_ENABLE */
		else if (udev->actconfig)
		} else {
		/* Only a configured device will accept the Set Feature
		* U1/U2_ENABLE
		*/
		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 @@ static int usb_disable_link_state(struct usb_hcd hcd, struct usb_device udev,
		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 @@ int usb_disable_lpm(struct usb_device *udev)
		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 @@ void usb_enable_lpm(struct usb_device *udev)

		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);

drivers/usb/core/sysfs.c

+26 −5

Original line number	Diff line number	Diff line
		@@ -531,7 +531,7 @@ static ssize_t usb2_lpm_besl_store(struct device *dev,
		}
		static DEVICE_ATTR_RW(usb2_lpm_besl);

		static ssize_t usb3_hardware_lpm_show(struct device *dev,
		static ssize_t usb3_hardware_lpm_u1_show(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct usb_device *udev = to_usb_device(dev);
		@@ -539,7 +539,7 @@ static ssize_t usb3_hardware_lpm_show(struct device *dev,

		usb_lock_device(udev);

		if (udev->usb3_lpm_enabled)
		if (udev->usb3_lpm_u1_enabled)
		p = "enabled";
		else
		p = "disabled";
		@@ -548,7 +548,26 @@ static ssize_t usb3_hardware_lpm_show(struct device *dev,

		return sprintf(buf, "%s\n", p);
		}
		static DEVICE_ATTR_RO(usb3_hardware_lpm);
		static DEVICE_ATTR_RO(usb3_hardware_lpm_u1);

		static ssize_t usb3_hardware_lpm_u2_show(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct usb_device *udev = to_usb_device(dev);
		const char *p;

		usb_lock_device(udev);

		if (udev->usb3_lpm_u2_enabled)
		p = "enabled";
		else
		p = "disabled";

		usb_unlock_device(udev);

		return sprintf(buf, "%s\n", p);
		}
		static DEVICE_ATTR_RO(usb3_hardware_lpm_u2);

		static struct attribute *usb2_hardware_lpm_attr[] = {
		&dev_attr_usb2_hardware_lpm.attr,
		@@ -562,7 +581,8 @@ static struct attribute_group usb2_hardware_lpm_attr_group = {
		};

		static struct attribute *usb3_hardware_lpm_attr[] = {
		&dev_attr_usb3_hardware_lpm.attr,
		&dev_attr_usb3_hardware_lpm_u1.attr,
		&dev_attr_usb3_hardware_lpm_u2.attr,
		NULL,
		};
		static struct attribute_group usb3_hardware_lpm_attr_group = {
		@@ -592,7 +612,8 @@ static int add_power_attributes(struct device *dev)
		if (udev->usb2_hw_lpm_capable == 1)
		rc = sysfs_merge_group(&dev->kobj,
		&usb2_hardware_lpm_attr_group);
		if (udev->lpm_capable == 1)
		if (udev->speed == USB_SPEED_SUPER &&
		udev->lpm_capable == 1)
		rc = sysfs_merge_group(&dev->kobj,
		&usb3_hardware_lpm_attr_group);
		}

include/linux/usb.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -511,6 +511,8 @@ struct usb3_lpm_parameters {
		* @usb2_hw_lpm_enabled: USB2 hardware LPM is enabled
		* @usb2_hw_lpm_allowed: Userspace allows USB 2.0 LPM to be enabled
		* @usb3_lpm_enabled: USB3 hardware LPM enabled
		* @usb3_lpm_u1_enabled: USB3 hardware U1 LPM enabled
		* @usb3_lpm_u2_enabled: USB3 hardware U2 LPM enabled
		* @string_langid: language ID for strings
		* @product: iProduct string, if present (static)
		* @manufacturer: iManufacturer string, if present (static)
		@@ -584,6 +586,8 @@ struct usb_device {
		unsigned usb2_hw_lpm_enabled:1;
		unsigned usb2_hw_lpm_allowed:1;
		unsigned usb3_lpm_enabled:1;
		unsigned usb3_lpm_u1_enabled:1;
		unsigned usb3_lpm_u2_enabled:1;
		int string_langid;

		/* static strings from the device */

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