From: Eric Miao <eric.miao@marvell.com>
Date: Mon, 8 Dec 2008 10:51:01 +0000 (+0800)
Subject: [ARM] pxafb: avoid the racing condition in pxafb_smart_thread
X-Git-Tag: v2.6.29-rc1~559^2~3^2~8
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=07f651c72ac0530033883c113939d9b9c7fa75e5;p=linux-2.6-omap-h63xx.git

[ARM] pxafb: avoid the racing condition in pxafb_smart_thread

fbi->state change shall really be protected by fbi->ctrlr_lock, where
the change is sheltered. There is a possibility that pxafb_smart_thread
will start update the LCD panel when fbi->state == C_ENABLE, while
all other initialization isn't done.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
---

diff --git a/drivers/video/pxafb.c b/drivers/video/pxafb.c
index 1e1c4ec0d3b..ab689597f25 100644
--- a/drivers/video/pxafb.c
+++ b/drivers/video/pxafb.c
@@ -794,11 +794,15 @@ static int pxafb_smart_thread(void *arg)
 		if (try_to_freeze())
 			continue;
 
+		mutex_lock(&fbi->ctrlr_lock);
+
 		if (fbi->state == C_ENABLE) {
 			inf->smart_update(&fbi->fb);
 			complete(&fbi->refresh_done);
 		}
 
+		mutex_unlock(&fbi->ctrlr_lock);
+
 		set_current_state(TASK_INTERRUPTIBLE);
 		schedule_timeout(30 * HZ / 1000);
 	}