2010-08-16 20:10:12

by Ondrej Zary

[permalink] [raw]
Subject: [PATCH] [RFC] cyber2000fb: avoid palette corruption at higher clocks

When 1280x1024@75Hz mode is set, console palette is not set properly -
sometimes the background is white, sometimes yellow and text colors are also
messed up. This does not happen at 1280x1024@60Hz and below.

It seems that the HW needs some time before setting the palette - maybe the
PLL needs more time to lock at higher speeds. This patch fixes the problem but
without knowing what register to check for PLL lock(?), the delay might be
excessive.

Signed-off-by: Ondrej Zary <[email protected]>

--- linux-2.6.35-rc3-/drivers/video/cyber2000fb.c 2010-08-15 21:13:39.000000000 +0200
+++ linux-2.6.35-rc3/drivers/video/cyber2000fb.c 2010-08-15 21:25:20.000000000 +0200
@@ -506,6 +506,9 @@ static void cyber2000fb_set_timing(struc
cyber2000_grphw(0xb9, 0x80, cfb);
cyber2000_grphw(0xb9, 0x00, cfb);

+ /* wait (for the PLL?) to avoid palette corruption at higher clocks */
+ msleep(1000);
+
cfb->ramdac_ctrl = hw->ramdac;
cyber2000fb_write_ramdac_ctrl(cfb);




--
Ondrej Zary


2010-08-16 21:06:47

by Russell King - ARM Linux

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Subject: Re: [PATCH] [RFC] cyber2000fb: avoid palette corruption at higher clocks

On Mon, Aug 16, 2010 at 10:09:54PM +0200, Ondrej Zary wrote:
> When 1280x1024@75Hz mode is set, console palette is not set properly -
> sometimes the background is white, sometimes yellow and text colors are also
> messed up. This does not happen at 1280x1024@60Hz and below.

I'm not going to have much time to look at your patches, and I
definitely want to test them on the NetWinder to make sure we
don't regress the primary platform that this driver is supporting.

I should have more time to look at them in September.

2010-08-16 22:02:33

by Ondrej Zary

[permalink] [raw]
Subject: Re: [PATCH] [RFC] cyber2000fb: avoid palette corruption at higher clocks

On Monday 16 August 2010 23:06:34 Russell King - ARM Linux wrote:
> On Mon, Aug 16, 2010 at 10:09:54PM +0200, Ondrej Zary wrote:
> > When 1280x1024@75Hz mode is set, console palette is not set properly -
> > sometimes the background is white, sometimes yellow and text colors are
> > also messed up. This does not happen at 1280x1024@60Hz and below.
>
> I'm not going to have much time to look at your patches, and I
> definitely want to test them on the NetWinder to make sure we
> don't regress the primary platform that this driver is supporting.
>
> I should have more time to look at them in September.

Thanks, I'll put the cards to sleep and take them out later.

--
Ondrej Zary