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usb: core: lpm: fix usb3_hardware_lpm sysfs node

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Commit 655fe4effe ("usbcore: add sysfs support to xHCI usb3
hardware LPM") introduced usb3_hardware_lpm sysfs node. This
doesn't show the correct status of USB3 U1 and U2 LPM status.

This patch fixes this by replacing usb3_hardware_lpm with two
nodes, usb3_hardware_lpm_u1 (for U1) and usb3_hardware_lpm_u2
(for U2), and recording the U1/U2 LPM status in right places.

This patch should be back-ported to kernels as old as 4.3,
that contains Commit 655fe4effe ("usbcore: add sysfs support
to xHCI usb3 hardware LPM").

Cc: stable@vger.kernel.org
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lu Baolu
2015-11-14 16:26:32 +08:00
committed by Greg Kroah-Hartman
parent c56a2b2bc6
commit bf5ce5bf3c
5 changed files with 75 additions and 26 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
drivers/usb/core/hub.c
View File

@@ -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);
} else {
/* Only a configured device will accept the Set Feature
* U1/U2_ENABLE
*/
if (udev->actconfig)
usb_set_device_initiated_lpm(udev, state, true);
/* Only a configured device will accept the Set Feature U1/U2_ENABLE */
else 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);

31
drivers/usb/core/sysfs.c
View File

@@ -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);
}