Re: [PATCH 2/3] video: fbdev: Check Standard Timing against DMT

[Tomi Valkeinen <tomi.valkeinen@ti.com>]

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On 03/12/14 23:49, David Ung wrote:
> Add the VESA Display Monitor Timing (DMT) table.
> During parsing of Standard Timings, it compare the 2 byte STD code
> with DMT to see what the VESA mode should be.  If there is no entry
> in the vesa_modes table or no match found, it fallsback to the
> GTF timings.
> 
> Signed-off-by: David Ung <davidu@nvidia.com>
> ---
>  drivers/video/fbdev/core/fbmon.c  | 20 ++++++----
>  drivers/video/fbdev/core/modedb.c | 84 +++++++++++++++++++++++++++++++++++++++
>  include/linux/fb.h                | 10 +++++
>  3 files changed, 107 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/video/fbdev/core/fbmon.c b/drivers/video/fbdev/core/fbmon.c
> index 5b0e313..aa1110a 100644
> --- a/drivers/video/fbdev/core/fbmon.c
> +++ b/drivers/video/fbdev/core/fbmon.c
> @@ -526,16 +526,22 @@ static int get_std_timing(unsigned char *block, struct fb_videomode *mode,
>  	refresh = (block[1] & 0x3f) + 60;
>  
>  	DPRINTK("      %dx%d@%dHz\n", xres, yres, refresh);
> -	for (i = 0; i < VESA_MODEDB_SIZE; i++) {
> -		if (vesa_modes[i].xres == xres &&
> -		    vesa_modes[i].yres == yres &&
> -		    vesa_modes[i].refresh == refresh) {
> -			*mode = vesa_modes[i];
> +	for (i = 0; i < DMT_SIZE; i++) {
> +		u32 std_2byte_code = block[0] << 8 | block[1];
> +
> +		if (std_2byte_code == dmt_modes[i].std_2byte_code) {
> +			if (!dmt_modes[i].mode)
> +				break;
> +			*mode = *dmt_modes[i].mode;
>  			mode->flag |= FB_MODE_IS_STANDARD;
> -			return 1;
> +			DPRINTK("        DMT id=%d\n", dmt_modes[i].dmt_id);
> +			break;
>  		}
>  	}
> -	calc_mode_timings(xres, yres, refresh, mode);
> +
> +	if (i == DMT_SIZE || !dmt_modes[i].mode)
> +		calc_mode_timings(xres, yres, refresh, mode);
> +
>  	return 1;
>  }

I think this could be made a bit cleaner.

The xres/yres/refresh calculation in get_std_timing doesn't matter for
the DMT code above. So in get_std_timing() you could first do the search
for the DMT mode, and if found, return from the function. After that the
code would do the GTF calculation.

 Tomi



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