From: Ondrej Zary <linux@rainbow-software.org>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: linux-fbdev@vger.kernel.org,
Kernel development list <linux-kernel@vger.kernel.org>
Subject: [PATCH] cyber2000fb: palette corruption at higher clocks
Date: Sun, 15 Aug 2010 19:51:11 +0000 [thread overview]
Message-ID: <201008152151.14175.linux@rainbow-software.org> (raw)
Hello,
I'm implementing EDID support for cyber2000fb and found a weird bug in
cyber2000fb driver. My monitor EDID reports 1280x1024@75Hz as best mode. When
this 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.
When I run "reset", it fixes the palette. But when I run it immediately after
loading the driver (i.e. "modprobe cyber2000fb mode_option\x1280x1024-8@75 &&
reset"), it does not help. "sleep 0.6" needs to be added before "reset" to
make it work.
It seems that the HW needs some time before setting the palette - maybe the
PLL needs more time to lock at higher speeds? Does anyone have some HW docs
to check this? 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 <linux@rainbow-software.org>
--- 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
reply other threads:[~2010-08-15 19:51 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=201008152151.14175.linux@rainbow-software.org \
--to=linux@rainbow-software.org \
--cc=linux-fbdev@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).