From: zwl <zwl@rock-chips.com>
Date: Wed, 2 Jul 2014 03:55:27 +0000 (+0800)
Subject: rk fb: add the judgement that if the variable dev_drv is null pointer
X-Git-Tag: firefly_0821_release~5006
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0c6b163418d97412095399c3ff9f68383cfb077e;p=firefly-linux-kernel-4.4.55.git

rk fb: add the judgement that if the variable dev_drv is null pointer
---

diff --git a/drivers/video/rockchip/rk_fb.c b/drivers/video/rockchip/rk_fb.c
index 2fbb3104e64b..261066da6fd1 100755
--- a/drivers/video/rockchip/rk_fb.c
+++ b/drivers/video/rockchip/rk_fb.c
@@ -566,7 +566,10 @@ u64 rk_fb_get_prmry_screen_framedone_t(void)
 {
 	struct rk_lcdc_driver *dev_drv = rk_get_prmry_lcdc_drv();
 
-	return dev_drv->frame_time.framedone_t;
+	if (unlikely(!dev_drv))
+		return 0;
+	else
+		return dev_drv->frame_time.framedone_t;
 }
 
 /*
@@ -575,8 +578,12 @@ u64 rk_fb_get_prmry_screen_framedone_t(void)
 int rk_fb_set_prmry_screen_status(int status)
 {
 	struct rk_lcdc_driver *dev_drv = rk_get_prmry_lcdc_drv();
-	struct rk_screen *screen = dev_drv->cur_screen;
+	struct rk_screen *screen;
 
+	if (unlikely(!dev_drv))
+		return 0;
+
+	screen = dev_drv->cur_screen;
 	switch (status) {
 	case SCREEN_PREPARE_DDR_CHANGE:
 		if (screen->type == SCREEN_MIPI
@@ -625,7 +632,11 @@ static struct rk_lcdc_driver *rk_get_extend_lcdc_drv(void)
 u32 rk_fb_get_prmry_screen_pixclock(void)
 {
 	struct rk_lcdc_driver *dev_drv = rk_get_prmry_lcdc_drv();
-	return dev_drv->pixclock;
+
+	if (unlikely(!dev_drv))
+		return 0;
+	else
+		return dev_drv->pixclock;
 }
 
 int rk_fb_poll_prmry_screen_vblank(void)