ACPI: thinkpad-acpi: dequeue all pending hot key events at once (v2.2)

Receive all pending HKEY events at once from a single notification, and don't
complain if the queue is empty.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NLen Brown <len.brown@intel.com>

drivers/misc/thinkpad_acpi.c

@@ -1196,9 +1196,30 @@ static void hotkey_notify(struct ibm_struct *ibm, u32 event)
 {
 	u32 hkey;
 	unsigned int keycode, scancode;
-	int send_acpi_ev = 0;
+	int send_acpi_ev;
+
+	if (event != 0x80) {
+		printk(IBM_ERR "unknown HKEY notification event %d\n", event);
+		/* forward it to userspace, maybe it knows how to handle it */
+		acpi_bus_generate_netlink_event(ibm->acpi->device->pnp.device_class,
+						ibm->acpi->device->dev.bus_id,
+						event, 0);
+		return;
+	}
+
+	while (1) {
+		if (!acpi_evalf(hkey_handle, &hkey, "MHKP", "d")) {
+			printk(IBM_ERR "failed to retrieve HKEY event\n");
+			return;
+		}
+
+		if (hkey == 0) {
+			/* queue empty */
+			return;
+		}
+
+		send_acpi_ev = 0;
 
-	if (event == 0x80 && acpi_evalf(hkey_handle, &hkey, "MHKP", "d")) {
 		switch (hkey >> 12) {
 		case 1:
 			/* 0x1000-0x1FFF: key presses */
@@ -1220,7 +1241,7 @@ static void hotkey_notify(struct ibm_struct *ibm, u32 event)
 			 * eat up known LID events */
 			if (hkey != 0x5001 && hkey != 0x5002) {
 				printk(IBM_ERR
-					"unknown LID-related hotkey event: 0x%04x\n",
+				       "unknown LID-related HKEY event: 0x%04x\n",
 				       hkey);
 				send_acpi_ev = 1;
 			}
@@ -1240,11 +1261,6 @@ static void hotkey_notify(struct ibm_struct *ibm, u32 event)
 			printk(IBM_NOTICE "unhandled HKEY event 0x%04x\n", hkey);
 			send_acpi_ev = 1;
 		}
-	} else {
-		printk(IBM_ERR "unknown hotkey notification event %d\n", event);
-		hkey = 0;
-		send_acpi_ev = 1;
-	}
 
 		/* Legacy events */
 		if (send_acpi_ev || hotkey_report_mode < 2)
@@ -1256,6 +1272,7 @@ static void hotkey_notify(struct ibm_struct *ibm, u32 event)
 							ibm->acpi->device->dev.bus_id,
 							event, hkey);
 		}
+	}
 }
 
 static void hotkey_resume(void)