/*---------------------- USB 3.0 Link PM functions ------------------------*/
+/* Service interval in nanoseconds = 2^(bInterval - 1) * 125us * 1000ns / 1us */
+static unsigned long long xhci_service_interval_to_ns(
+ struct usb_endpoint_descriptor *desc)
+{
+ return (1 << (desc->bInterval - 1)) * 125 * 1000;
+}
+
static u16 xhci_get_timeout_no_hub_lpm(struct usb_device *udev,
enum usb3_link_state state)
{
return USB3_LPM_DISABLED;
}
+/* Returns the hub-encoded U1 timeout value.
+ * The U1 timeout should be the maximum of the following values:
+ * - For control endpoints, U1 system exit latency (SEL) * 3
+ * - For bulk endpoints, U1 SEL * 5
+ * - For interrupt endpoints:
+ * - Notification EPs, U1 SEL * 3
+ * - Periodic EPs, max(105% of bInterval, U1 SEL * 2)
+ * - For isochronous endpoints, max(105% of bInterval, U1 SEL * 2)
+ */
+static u16 xhci_calculate_intel_u1_timeout(struct usb_device *udev,
+ struct usb_endpoint_descriptor *desc)
+{
+ unsigned long long timeout_ns;
+ int ep_type;
+ int intr_type;
+
+ ep_type = usb_endpoint_type(desc);
+ switch (ep_type) {
+ case USB_ENDPOINT_XFER_CONTROL:
+ timeout_ns = udev->u1_params.sel * 3;
+ break;
+ case USB_ENDPOINT_XFER_BULK:
+ timeout_ns = udev->u1_params.sel * 5;
+ break;
+ case USB_ENDPOINT_XFER_INT:
+ intr_type = usb_endpoint_interrupt_type(desc);
+ if (intr_type == USB_ENDPOINT_INTR_NOTIFICATION) {
+ timeout_ns = udev->u1_params.sel * 3;
+ break;
+ }
+ /* Otherwise the calculation is the same as isoc eps */
+ case USB_ENDPOINT_XFER_ISOC:
+ timeout_ns = xhci_service_interval_to_ns(desc);
+ timeout_ns = DIV_ROUND_UP(timeout_ns * 105, 100);
+ if (timeout_ns < udev->u1_params.sel * 2)
+ timeout_ns = udev->u1_params.sel * 2;
+ break;
+ default:
+ return 0;
+ }
+
+ /* The U1 timeout is encoded in 1us intervals. */
+ timeout_ns = DIV_ROUND_UP(timeout_ns, 1000);
+ /* Don't return a timeout of zero, because that's USB3_LPM_DISABLED. */
+ if (timeout_ns == USB3_LPM_DISABLED)
+ timeout_ns++;
+
+ /* If the necessary timeout value is bigger than what we can set in the
+ * USB 3.0 hub, we have to disable hub-initiated U1.
+ */
+ if (timeout_ns <= USB3_LPM_U1_MAX_TIMEOUT)
+ return timeout_ns;
+ dev_dbg(&udev->dev, "Hub-initiated U1 disabled "
+ "due to long timeout %llu ms\n", timeout_ns);
+ return xhci_get_timeout_no_hub_lpm(udev, USB3_LPM_U1);
+}
+
+/* Returns the hub-encoded U2 timeout value.
+ * The U2 timeout should be the maximum of:
+ * - 10 ms (to avoid the bandwidth impact on the scheduler)
+ * - largest bInterval of any active periodic endpoint (to avoid going
+ * into lower power link states between intervals).
+ * - the U2 Exit Latency of the device
+ */
+static u16 xhci_calculate_intel_u2_timeout(struct usb_device *udev,
+ struct usb_endpoint_descriptor *desc)
+{
+ unsigned long long timeout_ns;
+ unsigned long long u2_del_ns;
+
+ timeout_ns = 10 * 1000 * 1000;
+
+ if ((usb_endpoint_xfer_int(desc) || usb_endpoint_xfer_isoc(desc)) &&
+ (xhci_service_interval_to_ns(desc) > timeout_ns))
+ timeout_ns = xhci_service_interval_to_ns(desc);
+
+ u2_del_ns = udev->bos->ss_cap->bU2DevExitLat * 1000;
+ if (u2_del_ns > timeout_ns)
+ timeout_ns = u2_del_ns;
+
+ /* The U2 timeout is encoded in 256us intervals */
+ timeout_ns = DIV_ROUND_UP(timeout_ns, 256 * 1000);
+ /* If the necessary timeout value is bigger than what we can set in the
+ * USB 3.0 hub, we have to disable hub-initiated U2.
+ */
+ if (timeout_ns <= USB3_LPM_U2_MAX_TIMEOUT)
+ return timeout_ns;
+ dev_dbg(&udev->dev, "Hub-initiated U2 disabled "
+ "due to long timeout %llu ms\n", timeout_ns);
+ return xhci_get_timeout_no_hub_lpm(udev, USB3_LPM_U2);
+}
+
static u16 xhci_call_host_update_timeout_for_endpoint(struct xhci_hcd *xhci,
struct usb_device *udev,
struct usb_endpoint_descriptor *desc,
enum usb3_link_state state,
u16 *timeout)
{
+ if (state == USB3_LPM_U1) {
+ if (xhci->quirks & XHCI_INTEL_HOST)
+ return xhci_calculate_intel_u1_timeout(udev, desc);
+ } else {
+ if (xhci->quirks & XHCI_INTEL_HOST)
+ return xhci_calculate_intel_u2_timeout(udev, desc);
+ }
+
return USB3_LPM_DISABLED;
}
return 0;
}
+static int xhci_check_intel_tier_policy(struct usb_device *udev,
+ enum usb3_link_state state)
+{
+ struct usb_device *parent;
+ unsigned int num_hubs;
+
+ if (state == USB3_LPM_U2)
+ return 0;
+
+ /* Don't enable U1 if the device is on a 2nd tier hub or lower. */
+ for (parent = udev->parent, num_hubs = 0; parent->parent;
+ parent = parent->parent)
+ num_hubs++;
+
+ if (num_hubs < 2)
+ return 0;
+
+ dev_dbg(&udev->dev, "Disabling U1 link state for device"
+ " below second-tier hub.\n");
+ dev_dbg(&udev->dev, "Plug device into first-tier hub "
+ "to decrease power consumption.\n");
+ return -E2BIG;
+}
+
static int xhci_check_tier_policy(struct xhci_hcd *xhci,
struct usb_device *udev,
enum usb3_link_state state)
{
+ if (xhci->quirks & XHCI_INTEL_HOST)
+ return xhci_check_intel_tier_policy(udev, state);
return -EINVAL;
}
projects / karo-tx-linux.git / blobdiff