From: Tasslehoff Kjappfot <tasskjapp@gmail.com>
To: linux-omap@vger.kernel.org
Subject: Patch to fix swapping of front and back porches when reading from modedb.c
Date: Wed, 08 Sep 2010 15:39:27 +0200 [thread overview]
Message-ID: <4C87920F.9050005@gmail.com> (raw)
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Hi list :-)
I had trouble getting a standard 800x600@60Hz VGA signal to display correctly on my monitors. Measuring the output showed that the front and back porches were swapped both for hsync and vsync. After reading the source I think I found the error in drivers/video/omap2/omapfb/omapfb-main.c. Patch attached.
http://www.xfree86.org/3.3.6/fbdev6.html shows the way it should be, but todays code sets:
hfp = left margin
hbp = right margin
vfp = upper margin
vbp = lower margin
I tested a patched kernel with 800x600@60Hz on two different monitors and a vga grabber, and it solved my issues.
Regards,
Tassle
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>From f6a0d18c16bfc827e18356b11c4e3cd96b836787 Mon Sep 17 00:00:00 2001
From: Tasslehoff Kjappfot <tasskjapp@gmail.com>
Date: Wed, 8 Sep 2010 12:46:14 +0200
Subject: [PATCH] swap front and back porches for both hsync and vsync
---
drivers/video/omap2/omapfb/omapfb-main.c | 16 ++++++++--------
1 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/video/omap2/omapfb/omapfb-main.c b/drivers/video/omap2/omapfb/omapfb-main.c
index 015831b..69e6a08 100644
--- a/drivers/video/omap2/omapfb/omapfb-main.c
+++ b/drivers/video/omap2/omapfb/omapfb-main.c
@@ -711,10 +711,10 @@ int check_fb_var(struct fb_info *fbi, struct fb_var_screeninfo *var)
var->pixclock = timings.pixel_clock != 0 ?
KHZ2PICOS(timings.pixel_clock) :
0;
- var->left_margin = timings.hfp;
- var->right_margin = timings.hbp;
- var->upper_margin = timings.vfp;
- var->lower_margin = timings.vbp;
+ var->left_margin = timings.hbp;
+ var->right_margin = timings.hfp;
+ var->upper_margin = timings.vbp;
+ var->lower_margin = timings.vfp;
var->hsync_len = timings.hsw;
var->vsync_len = timings.vsw;
} else {
@@ -1992,10 +1992,10 @@ static int omapfb_mode_to_timings(const char *mode_str,
if (r != 0) {
timings->pixel_clock = PICOS2KHZ(var.pixclock);
- timings->hfp = var.left_margin;
- timings->hbp = var.right_margin;
- timings->vfp = var.upper_margin;
- timings->vbp = var.lower_margin;
+ timings->hbp = var.left_margin;
+ timings->hfp = var.right_margin;
+ timings->vbp = var.upper_margin;
+ timings->vfp = var.lower_margin;
timings->hsw = var.hsync_len;
timings->vsw = var.vsync_len;
timings->x_res = var.xres;
--
1.7.0.4
next reply other threads:[~2010-09-08 13:34 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-08 13:39 Tasslehoff Kjappfot [this message]
2010-09-08 13:38 ` Patch to fix swapping of front and back porches when reading from modedb.c Russ Dill
2010-09-08 13:47 ` Tasslehoff Kjappfot
2010-09-09 8:28 ` Tomi Valkeinen
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