diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-usb | 12 | ||||
| -rw-r--r-- | drivers/usb/core/hub.c | 7 | ||||
| -rw-r--r-- | drivers/usb/core/sysfs.c | 10 | ||||
| -rw-r--r-- | include/linux/usb.h | 8 |
4 files changed, 30 insertions, 7 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index 6df4e6f57560..5f75f8f7df34 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -208,3 +208,15 @@ Description: such as ACPI. This file will read either "removable" or "fixed" if the information is available, and "unknown" otherwise. + +What: /sys/bus/usb/devices/.../ltm_capable +Date: July 2012 +Contact: Sarah Sharp <sarah.a.sharp@linux.intel.com> +Description: + USB 3.0 devices may optionally support Latency Tolerance + Messaging (LTM). They indicate their support by setting a bit + in the bmAttributes field of their SuperSpeed BOS descriptors. + If that bit is set for the device, ltm_capable will read "yes". + If the device doesn't support LTM, the file will read "no". + The file will be present for all speeds of USB devices, and will + always read "no" for USB 1.1 and USB 2.0 devices. diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index b5bd6bd8fd12..d739f966b5a8 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2610,13 +2610,6 @@ static int check_port_resume_type(struct usb_device *udev, return status; } -static bool usb_device_supports_ltm(struct usb_device *udev) -{ - if (udev->speed != USB_SPEED_SUPER || !udev->bos || !udev->bos->ss_cap) - return false; - return udev->bos->ss_cap->bmAttributes & USB_LTM_SUPPORT; -} - int usb_disable_ltm(struct usb_device *udev) { struct usb_hcd *hcd = bus_to_hcd(udev->bus); diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index 777f03c37725..682e8256b95d 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/include/linux/usb.h b/include/linux/usb.h index f29831bad235..f8506ed0f97b 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -636,6 +636,14 @@ extern void usb_unlocked_enable_lpm(struct usb_device *udev); extern int usb_disable_ltm(struct usb_device *udev); extern void usb_enable_ltm(struct usb_device *udev); +static inline bool usb_device_supports_ltm(struct usb_device *udev) +{ + if (udev->speed != USB_SPEED_SUPER || !udev->bos || !udev->bos->ss_cap) + return false; + return udev->bos->ss_cap->bmAttributes & USB_LTM_SUPPORT; +} + + /*-------------------------------------------------------------------------*/ /* for drivers using iso endpoints */ |