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cyber2000fb: avoid palette corruption at higher clocks

RFC PATCH In review Ondrej Zary 2 participants 3 messages Aug 16, 2010 Framebuffer layer

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RFC PATCH 1/1 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.

drivers/video/cyber2000fb.c +3 -0
@@ -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);
 
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Ondrej Zary
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Quoted 3 lines · Ondrej Zary

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.

#2 lore raw
Quoted 10 lines · On Monday 16 August 2010 23:06:34 Russell King - ARM Linux wrote:
Quoted 3 lines · Ondrej Zary

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.

Signature · 1 line
Ondrej Zary