Input: evdev - fix bug in checking duplicate clock change request

clk_type and clkid stores different predefined clock identification
values so they cannot be compared for checking duplicate clock change
request. Therefore, lets fix it to avoid unexpected results.

Signed-off-by: Aniroop Mathur <a.mathur@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 19 insertions, 17 deletions

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 6b10f5b29218..e9ae3d500a55 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -56,7 +56,7 @@ struct evdev_client {
         struct fasync_struct *fasync;
         struct evdev *evdev;
         struct list_head node;
-        int clk_type;
+        unsigned int clk_type;
         bool revoked;
         unsigned long *evmasks[EV_CNT];
         unsigned int bufsize;
@@ -191,37 +191,39 @@ static void evdev_queue_syn_dropped(struct evdev_client *client)
 static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid)
 {
         unsigned long flags;
-
-        if (client->clk_type == clkid)
-                return 0;
+        unsigned int clk_type;
 
         switch (clkid) {
 
         case CLOCK_REALTIME:
-                client->clk_type = EV_CLK_REAL;
+                clk_type = EV_CLK_REAL;
                 break;
         case CLOCK_MONOTONIC:
-                client->clk_type = EV_CLK_MONO;
+                clk_type = EV_CLK_MONO;
                 break;
         case CLOCK_BOOTTIME:
-                client->clk_type = EV_CLK_BOOT;
+                clk_type = EV_CLK_BOOT;
                 break;
         default:
                 return -EINVAL;
         }
 
-        /*
-         * Flush pending events and queue SYN_DROPPED event,
-         * but only if the queue is not empty.
-         */
-        spin_lock_irqsave(&client->buffer_lock, flags);
+        if (client->clk_type != clk_type) {
+                client->clk_type = clk_type;
 
-        if (client->head != client->tail) {
-                client->packet_head = client->head = client->tail;
-                __evdev_queue_syn_dropped(client);
-        }
+                /*
+                 * Flush pending events and queue SYN_DROPPED event,
+                 * but only if the queue is not empty.
+                 */
+                spin_lock_irqsave(&client->buffer_lock, flags);
 
-        spin_unlock_irqrestore(&client->buffer_lock, flags);
+                if (client->head != client->tail) {
+                        client->packet_head = client->head = client->tail;
+                        __evdev_queue_syn_dropped(client);
+                }
+
+                spin_unlock_irqrestore(&client->buffer_lock, flags);
+        }
 
         return 0;
 }