Re: [PATCH/RFC v2] video: fbdev: atari: Fix TT High video mode

From: Andreas Schwab <schwab@linux-m68k.org>
To: Sam Ravnborg <sam@ravnborg.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
	Michael Schmitz <schmitzmic@gmail.com>,
	linux-fbdev@vger.kernel.org, linux-m68k@vger.kernel.org,
	dri-devel@lists.freedesktop.org
Subject: Re: [PATCH/RFC v2] video: fbdev: atari: Fix TT High video mode
Date: Sun, 01 Nov 2020 13:46:59 +0100	[thread overview]
Message-ID: <874km91by4.fsf@igel.home> (raw)
In-Reply-To: <20201101112915.GB1263673@ravnborg.org> (Sam Ravnborg's message of "Sun, 1 Nov 2020 12:29:15 +0100")

On Nov 01 2020, Sam Ravnborg wrote:

> Hi Geert.
>
> On Sun, Nov 01, 2020 at 11:29:41AM +0100, Geert Uytterhoeven wrote:
>> The horizontal resolution (640) for the TT High video mode (1280x960) is
>> definitely bogus.  While fixing that, correct the timings to match the
>> TTM195 service manual.
>> 
>> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
>> ---
>> Untested on actual hardware, hence the RFC.
>> 
>> v2:
>>   - Use correct base.
>> ---
>>  drivers/video/fbdev/atafb.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/video/fbdev/atafb.c b/drivers/video/fbdev/atafb.c
>> index f253daa05d9d3872..5ecf3ec9f94cb720 100644
>> --- a/drivers/video/fbdev/atafb.c
>> +++ b/drivers/video/fbdev/atafb.c
>> @@ -495,8 +495,8 @@ static struct fb_videomode atafb_modedb[] __initdata = {
>>  		"tt-mid", 60, 640, 480, 31041, 120, 100, 8, 16, 140, 30,
>>  		0, FB_VMODE_NONINTERLACED | FB_VMODE_YWRAP
>>  	}, {
>> -		/* 1280x960, 29 kHz, 60 Hz (TT high) */
>> -		"tt-high", 57, 640, 960, 31041, 120, 100, 8, 16, 140, 30,
>> +		/* 1280x960, 72 kHz, 72 Hz (TT high) */
>> +		"tt-high", 57, 1280, 960, 7761, 260, 60, 36, 4, 192, 4,
>>  		0, FB_VMODE_NONINTERLACED | FB_VMODE_YWRAP
>
> Well-spotted. The change of 640 => 1280 is surely right.
> I have a harder time understanding why the change of pixclock from 31041
> to 7761 is correct. All other modes have a pixclock close to or equal
> to 32000 - so it looks strange this one is off.

According to the Profibuch the pixclock should be about 95000.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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