@@ -37,6 +37,71 @@ bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
}
EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);
+#define UUID_USB_CONTROLLER_DSM "ce2ee385-00e6-48cb-9f05-2edb927c4899"
+#define USB_DSM_DISABLE_U1_U2_FOR_PORT 5
+
+/**
+ * usb_acpi_port_lpm_incapable - check if lpm should be disabled for a port.
+ * @hdev: USB device belonging to the usb hub
+ * @index: zero based port index
+ *
+ * Some USB3 ports may not support USB3 link power management U1/U2 states
+ * due to different retimer setup. ACPI provides _DSM method which returns 0x01
+ * if U1 and U2 states should be disabled. Evaluate _DSM with:
+ * Arg0: UUID = ce2ee385-00e6-48cb-9f05-2edb927c4899
+ * Arg1: Revision ID = 0
+ * Arg2: Function Index = 5
+ * Arg3: (empty)
+ *
+ * Return 1 if USB3 port is LPM incapable, negative on error, otherwise 0
+ */
+
+int usb_acpi_port_lpm_incapable(struct usb_device *hdev, int index)
+{
+ union acpi_object *obj;
+ acpi_handle port_handle;
+ int port1 = index + 1;
+ guid_t guid;
+ int ret;
+
+ ret = guid_parse(UUID_USB_CONTROLLER_DSM, &guid);
+ if (ret)
+ return ret;
+
+ port_handle = usb_get_hub_port_acpi_handle(hdev, port1);
+ if (!port_handle) {
+ dev_dbg(&hdev->dev, "port-%d no acpi handle\n", port1);
+ return -ENODEV;
+ }
+
+ if (!acpi_check_dsm(port_handle, &guid, 0,
+ BIT(USB_DSM_DISABLE_U1_U2_FOR_PORT))) {
+ dev_dbg(&hdev->dev, "port-%d no _DSM function %d\n",
+ port1, USB_DSM_DISABLE_U1_U2_FOR_PORT);
+ return -ENODEV;
+ }
+
+ obj = acpi_evaluate_dsm(port_handle, &guid, 0,
+ USB_DSM_DISABLE_U1_U2_FOR_PORT, NULL);
+
+ if (!obj)
+ return -ENODEV;
+
+ if (obj->type != ACPI_TYPE_INTEGER) {
+ dev_dbg(&hdev->dev, "evaluate port-%d _DSM failed\n", port1);
+ ACPI_FREE(obj);
+ return -EINVAL;
+ }
+
+ if (obj->integer.value == 0x01)
+ ret = 1;
+
+ ACPI_FREE(obj);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(usb_acpi_port_lpm_incapable);
+
/**
* usb_acpi_set_power_state - control usb port's power via acpi power
* resource
@@ -774,11 +774,14 @@ extern struct device *usb_intf_get_dma_device(struct usb_interface *intf);
extern int usb_acpi_set_power_state(struct usb_device *hdev, int index,
bool enable);
extern bool usb_acpi_power_manageable(struct usb_device *hdev, int index);
+extern int usb_acpi_port_lpm_incapable(struct usb_device *hdev, int index);
#else
static inline int usb_acpi_set_power_state(struct usb_device *hdev, int index,
bool enable) { return 0; }
static inline bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
{ return true; }
+static inline int usb_acpi_port_lpm_incapable(struct usb_device *hdev, int index)
+ { return 0; }
#endif
/* USB autosuspend and autoresume */