Adds abitilty to tune L1 timeout (inactivity timer for usb2 link sleep)
and BESL (best effort service latency)via sysfs.
This also adds a new usb2_lpm_parameters structure with those variables to
struct usb_device.
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
---
drivers/usb/core/sysfs.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++
drivers/usb/host/xhci.c | 6 +++-
include/linux/usb.h | 17 ++++++++++++++
3 files changed, 75 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index aa38db4..b6141d5 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -497,8 +497,62 @@ set_usb2_hardware_lpm(struct device *dev, struct device_attribute *attr,
static DEVICE_ATTR(usb2_hardware_lpm, S_IRUGO | S_IWUSR, show_usb2_hardware_lpm,
set_usb2_hardware_lpm);
+static ssize_t
+show_usb2_lpm_l1_timeout(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct usb_device *udev = to_usb_device(dev);
+ return sprintf(buf, "%d\n", udev->l1_params.timeout);
+}
+
+static ssize_t
+set_usb2_lpm_l1_timeout(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct usb_device *udev = to_usb_device(dev);
+ int timeout;
+
+ if (sscanf(buf, "%d", &timeout) != 1 || timeout < 0 || timeout > 255)
+ return -EINVAL;
+
+ udev->l1_params.timeout = timeout;
+
+ return count;
+}
+
+static DEVICE_ATTR(usb2_lpm_l1_timeout, S_IRUGO | S_IWUSR,
+ show_usb2_lpm_l1_timeout, set_usb2_lpm_l1_timeout);
+
+static ssize_t
+show_usb2_lpm_besl(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct usb_device *udev = to_usb_device(dev);
+ return sprintf(buf, "%d\n", udev->l1_params.besl);
+}
+
+static ssize_t
+set_usb2_lpm_besl(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct usb_device *udev = to_usb_device(dev);
+ int besl;
+
+ if (sscanf(buf, "%d", &besl) != 1 || besl < 0 || besl > 15)
+ return -EINVAL;
+
+ udev->l1_params.besl = besl;
+
+ return count;
+}
+
+static DEVICE_ATTR(usb2_lpm_besl, S_IRUGO | S_IWUSR,
+ show_usb2_lpm_besl, set_usb2_lpm_besl);
+
static struct attribute *usb2_hardware_lpm_attr[] = {
&dev_attr_usb2_hardware_lpm.attr,
+ &dev_attr_usb2_lpm_l1_timeout.attr,
+ &dev_attr_usb2_lpm_besl.attr,
NULL,
};
static struct attribute_group usb2_hardware_lpm_attr_group = {
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 22932d9..da4215f 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3900,7 +3900,7 @@ static int xhci_calculate_hird_besl(struct xhci_hcd *xhci,
static int xhci_calculate_usb2_hw_lpm_params(struct usb_device *udev)
{
u32 field;
- int l1 = XHCI_L1_TIMEOUT;
+ int l1 = udev->l1_params.timeout;
int besld = 0;
int hirdm = 0;
@@ -4088,7 +4088,7 @@ int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd,
(field & USB_BESL_BASELINE_VALID))
hird = USB_GET_BESL_BASELINE(field);
else
- hird = XHCI_DEFAULT_BESL;
+ hird = udev->l1_params.besl;
exit_latency = xhci_besl_encoding[hird];
spin_unlock_irqrestore(&xhci->lock, flags);
@@ -4178,6 +4178,8 @@ int xhci_update_device(struct usb_hcd *hcd, struct usb_device *udev)
if (xhci->hw_lpm_support == 1 &&
xhci_check_usb2_port_capability(xhci, portnum, XHCI_HLC)) {
udev->usb2_hw_lpm_capable = 1;
+ udev->l1_params.timeout = XHCI_L1_TIMEOUT;
+ udev->l1_params.besl = XHCI_DEFAULT_BESL;
if (xhci_check_usb2_port_capability(xhci, portnum,
XHCI_BLC))
udev->usb2_hw_lpm_besl_capable = 1;
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 3a1b864..08f6c63 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -394,6 +394,21 @@ enum usb_port_connect_type {
};
/*
+ * USB 2.0 Link Power Management (LPM) parameters.
+ */
+struct usb2_lpm_parameters {
+ /* Best effort service latency indicate how long the host will drive
+ * resume on an exit from L1.
+ */
+ unsigned int besl;
+
+ /* Timeout value for the L1 inactivity timer (LPM Timer). When the timer
+ * counts to zero, the parent hub will initiate an LPM transition to L1.
+ */
+ int timeout;
+};
+
+/*
* USB 3.0 Link Power Management (LPM) parameters.
*
* PEL and SEL are USB 3.0 Link PM latencies for device-initiated LPM exit.
@@ -488,6 +503,7 @@ struct usb3_lpm_parameters {
* specific data for the device.
* @slot_id: Slot ID assigned by xHCI
* @removable: Device can be physically removed from this port
+ * @l1_params: best effor service latency for USB2 L1 LPM state, and L1 timeout.
* @u1_params: exit latencies for USB3 U1 LPM state, and hub-initiated timeout.
* @u2_params: exit latencies for USB3 U2 LPM state, and hub-initiated timeout.
* @lpm_disable_count: Ref count used by usb_disable_lpm() and usb_enable_lpm()
@@ -568,6 +584,7 @@ struct usb_device {
struct wusb_dev *wusb_dev;
int slot_id;
enum usb_device_removable removable;
+ struct usb2_lpm_parameters l1_params;
struct usb3_lpm_parameters u1_params;
struct usb3_lpm_parameters u2_params;
unsigned lpm_disable_count;
--
1.7.4.1
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