Re: [RFC] [PATCH] omapfb: Fix 12-bit display (RGB444 color mode) handling

[Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>]

Tomi Valkeinen wrote:
> On Thu, 2010-01-14 at 21:25 +0100, ext Janusz Krzysztofik wrote:
>> Support for RGB444 (12-bit) pixel format has been introduced into omapfb/lcdc 
>> by Mark Underwood on 2006-05-26 (commit 
>> f74edb6668aad9fc8e81585861b18f996c78a574) in preparation for Amstrad Delta 
>> (E3) videophone LCD display support.
> 
> I haven't seen any comments on this. Shall I apply it to my tree?
> 
>  Tomi

Tomi,

I'm not sure if I am the right person to decide whether my patch should 
be accepted or not and what tree it should be applied to, but if you are 
willing to take it than I'm happy.

BTW, could you also consider taking my other long waiting patch that 
touches drivers/video/omap: http://patchwork.kernel.org/patch/66649/ ?

Thanks,
Janusz


>> Before the Amstrad Delta LCD patch by Jonathan McDowell was applied (on 
>> 2006-08-04, commit 8d22fb2ea004cdb6379b54c1a8fd1546cfe40ed7), omapfb and lcdc 
>> code was changed substantially (commit 
>> e563dc81aa01bd8bbb01bc53975a15c398715f62 dated 2006-06-26) in a way that broke 
>> Mark's 12-bit display support. Than, a patch by Jonathan, that supposed to 
>> correct the problem, was introduced immediatelly (on 2006-08-04, commit 
>> e10a75b49e7a57ae17c28b705153c70eba15a8ef).
>>
>> As a result, the Amstrad Delta display was working correctly at boot time, 
>> with fbset reporting:
>>
>> 	geometry 480 320 480 320 16
>> 	...
>> 	rgba 4/8,4/4,4/0,0/0
>>
>> However, after first framebuffer reinitialization, colors were no longer being 
>> displayed correctly and fbset was reporting:
>>
>>         rgba 5/11,6/5,5/0,0/0
>>
>> The patch tries to correct the issue by setting plane->color_mode depending on 
>> panel->bpp, not var->bits_per_pixel.
>>
>> Created and tested on Amstrad Delta against linux-2.6.33-rc3.
>>
>> Signed-off-by: Janusz Krzysztofik <jkrzysz@tis.icnet.pl>
>>
>> ---
>> --- git/drivers/video/omap/omapfb_main.c.orig	2010-01-14 19:30:23.000000000 +0100
>> +++ git/drivers/video/omap/omapfb_main.c	2010-01-14 20:31:18.000000000 +0100
>> @@ -473,10 +473,11 @@ static int set_color_mode(struct omapfb_
>>  		return 0;
>>  	case 12:
>>  		var->bits_per_pixel = 16;
>> -		plane->color_mode = OMAPFB_COLOR_RGB444;
>> -		return 0;
>>  	case 16:
>> -		plane->color_mode = OMAPFB_COLOR_RGB565;
>> +		if (plane->fbdev->panel->bpp == 12)
>> +			plane->color_mode = OMAPFB_COLOR_RGB444;
>> +		else
>> +			plane->color_mode = OMAPFB_COLOR_RGB565;
>>  		return 0;
>>  	default:
>>  		return -EINVAL;
> 
>