From: Ben Nizette Date: Tue, 16 Jun 2009 22:34:24 +0000 (-0700) Subject: atmel-lcdc: fix pixclock upper bound detection X-Git-Tag: v2.6.31-rc1~299^2~18 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=97b9a5a28b5fd02ceb3fcccee05e39dd62e4f474;p=platform%2Fkernel%2Flinux-exynos.git atmel-lcdc: fix pixclock upper bound detection AFAICT the code which checks that the requested pixclock value is within bounds is incorrect. It ensures that the lcdc core clock is at least (bytes per pixel) times higher than the pixel clock rather than just greater than or equal to. There are tighter restrictions on the pixclock value as a function of bus width for STN panels but even then it isn't a simple relationship as currently checked for. IMO either something like the below patch should be applied or else more detailed checking logic should be implemented which takes in to account the panel type as well. Signed-off-by: Ben Nizette Acked-by: Nicolas Ferre Cc: Haavard Skinnemoen Cc: Daniel Glockner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c index 2fb63f6..5afd644 100644 --- a/drivers/video/atmel_lcdfb.c +++ b/drivers/video/atmel_lcdfb.c @@ -345,7 +345,7 @@ static int atmel_lcdfb_check_var(struct fb_var_screeninfo *var, dev_dbg(dev, " bpp: %u\n", var->bits_per_pixel); dev_dbg(dev, " clk: %lu KHz\n", clk_value_khz); - if ((PICOS2KHZ(var->pixclock) * var->bits_per_pixel / 8) > clk_value_khz) { + if (PICOS2KHZ(var->pixclock) > clk_value_khz) { dev_err(dev, "%lu KHz pixel clock is too fast\n", PICOS2KHZ(var->pixclock)); return -EINVAL; }