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From: "Ville Syrjälä" <syrjala@sci.fi>
To: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: spock@gentoo.org,
	Linux-fbdev-devel <linux-fbdev-devel@lists.sourceforge.net>
Subject: Re: Fix 8bpp RGB fields length
Date: Mon, 2 Mar 2009 15:02:02 +0200	[thread overview]
Message-ID: <20090302130202.GA6298@sci.fi> (raw)
In-Reply-To: <20090301215556.8631c63c.krzysztof.h1@poczta.fm>

On Sun, Mar 01, 2009 at 09:55:56PM +0100, Krzysztof Helt wrote:
> Hi,
> 
> I found that some fbdev drivers set RGB field's lengths incorrectly
> to 6 bits. This is incorrect as the field's length says how many bits
> has a color index when using color palette (6 bits = 64 colors).

A slight omission in the fbdev API I suppose since the LUT entries are
nearly always 3*8bits wide. VGA being the exception.

> Fix this error in uvesafb by dropping DAC switching to 8 bits 
> completely. Advantage of this approach is making the driver shorter,
> disadvantage is that some color fidelity is lost.

I don't see much point in dropping this. It would reduce the image
quality and it looks like after your first fix this code would amount
to less than a dozen lines. But not my call anyway.

-- 
Ville Syrjälä
syrjala@sci.fi
http://www.sci.fi/~syrjala/

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  reply	other threads:[~2009-03-02 13:02 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-01 20:55 Fix 8bpp RGB fields length Krzysztof Helt
2009-03-02 13:02 ` Ville Syrjälä [this message]
2009-03-02 17:02   ` Krzysztof Helt
2009-03-02 17:40     ` Ville Syrjälä
2009-03-29 19:14     ` Michal Januszewski
2009-03-29 19:26       ` Geert Uytterhoeven
2009-03-29 21:18         ` Ville Syrjälä

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