From: zwl <zwl@rock-chips.com>
Date: Fri, 4 Jul 2014 01:29:04 +0000 (+0800)
Subject: rk screen: add the judgement if the variable rk_screen is null pointer
X-Git-Tag: firefly_0821_release~5000
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0e6a39bfec201f5bad0b762c232daefc69bb248a;p=firefly-linux-kernel-4.4.55.git

rk screen: add the judgement if the variable rk_screen is null pointer
---

diff --git a/drivers/video/rockchip/screen/rk_screen.c b/drivers/video/rockchip/screen/rk_screen.c
index 242ba4fb668a..0c031275d414 100755
--- a/drivers/video/rockchip/screen/rk_screen.c
+++ b/drivers/video/rockchip/screen/rk_screen.c
@@ -7,12 +7,18 @@
 static struct rk_screen *rk_screen;
 int  rk_fb_get_prmry_screen(struct rk_screen *screen)
 {
+	if (unlikely(!rk_screen) || unlikely(!screen))
+		return -1;
+
 	memcpy(screen, rk_screen, sizeof(struct rk_screen));
 	return 0;
 }
 
 int rk_fb_set_prmry_screen(struct rk_screen *screen)
 {
+	if (unlikely(!rk_screen) || unlikely(!screen))
+		return -1;
+
 	rk_screen->lcdc_id = screen->lcdc_id;
 	rk_screen->screen_id = screen->screen_id;
 	rk_screen->x_mirror = screen->x_mirror;
@@ -27,16 +33,22 @@ int rk_fb_set_prmry_screen(struct rk_screen *screen)
 size_t get_fb_size(void)
 {
 	size_t size = 0;
-	int xres = rk_screen->mode.xres;
-	int yres = rk_screen->mode.yres;
+	u32 xres = 0;
+	u32 yres = 0;
+
+	if (unlikely(!rk_screen))
+		return 0;
+
+	xres = rk_screen->mode.xres;
+	yres = rk_screen->mode.yres;
 
-	/*align as 64 bytes(16*4) in an odd number of times*/
+	/* align as 64 bytes(16*4) in an odd number of times */
 	xres = ALIGN_64BYTE_ODD_TIMES(xres, ALIGN_PIXEL_64BYTE_RGB8888);
 
 	#if defined(CONFIG_THREE_FB_BUFFER)
-		size = (xres * yres << 2) * 3; //three buffer
+		size = (xres * yres << 2) * 3;	/* three buffer */
 	#else
-		size = (xres * yres << 2) << 1; //two buffer
+		size = (xres * yres << 2) << 1; /* two buffer */
 	#endif
 	return ALIGN(size, SZ_1M);
 }