Input: i8042 - retry failed CTR writes when resuming

There are systems that fail in i8042_resume() with

i8042: Can't write CTR to resume

as i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR) fails even though the
controller claimed itself to be ready before.

One retry after failing write fixes the problems on the failing systems.

Reported-by: Helmut Schaa <[e-mail]>
Signed-off-by: Jiri Kosina <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/serio/i8042.c

···
 	i8042_ctr |= I8042_CTR_AUXDIS | I8042_CTR_KBDDIS;
 	i8042_ctr &= ~(I8042_CTR_AUXINT | I8042_CTR_KBDINT);
 	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
-		printk(KERN_ERR "i8042: Can't write CTR to resume\n");
-		return -EIO;
+		printk(KERN_WARNING "i8042: Can't write CTR to resume, retrying...\n");
+		msleep(50);
+		if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) {
+			printk(KERN_ERR "i8042: CTR write retry failed\n");
+			return -EIO;
+		}
 	}