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authorHaavard Skinnemoen <hskinnemoen@atmel.com>2008-02-06 01:39:11 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-06 10:41:15 -0800
commit162b3a084904a1d6ef1553782b8573885d5f900b (patch)
treed525a8f16852d80175555d3e28c52fb1f7d98bc0 /drivers/video/atmel_lcdfb.c
parent529e55b6a57bda6df9e45eb268589efc70f63303 (diff)
atmel_lcdfb: validate display timings
Setting a display timing parameter too high or too low may cause it to wrap around and thus become completely wrong. Validate the timings in atmel_lcdfb_check_var() and saturate to the highest or lowest possible value if necessary. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: "Antonino A. Daplas" <adaplas@pol.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/video/atmel_lcdfb.c')
-rw-r--r--drivers/video/atmel_lcdfb.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c
index f8e711147501..5d22ea532e42 100644
--- a/drivers/video/atmel_lcdfb.c
+++ b/drivers/video/atmel_lcdfb.c
@@ -203,6 +203,26 @@ static int atmel_lcdfb_check_var(struct fb_var_screeninfo *var,
var->transp.offset = var->transp.length = 0;
var->xoffset = var->yoffset = 0;
+ /* Saturate vertical and horizontal timings at maximum values */
+ var->vsync_len = min_t(u32, var->vsync_len,
+ (ATMEL_LCDC_VPW >> ATMEL_LCDC_VPW_OFFSET) + 1);
+ var->upper_margin = min_t(u32, var->upper_margin,
+ ATMEL_LCDC_VBP >> ATMEL_LCDC_VBP_OFFSET);
+ var->lower_margin = min_t(u32, var->lower_margin,
+ ATMEL_LCDC_VFP);
+ var->right_margin = min_t(u32, var->right_margin,
+ (ATMEL_LCDC_HFP >> ATMEL_LCDC_HFP_OFFSET) + 1);
+ var->hsync_len = min_t(u32, var->hsync_len,
+ (ATMEL_LCDC_HPW >> ATMEL_LCDC_HPW_OFFSET) + 1);
+ var->left_margin = min_t(u32, var->left_margin,
+ ATMEL_LCDC_HBP + 1);
+
+ /* Some parameters can't be zero */
+ var->vsync_len = max_t(u32, var->vsync_len, 1);
+ var->right_margin = max_t(u32, var->right_margin, 1);
+ var->hsync_len = max_t(u32, var->hsync_len, 1);
+ var->left_margin = max_t(u32, var->left_margin, 1);
+
switch (var->bits_per_pixel) {
case 1:
case 2: