On Wed, Sep 01, 2010 at 09:44:48, Caglar Akyuz wrote:
> On Wednesday 01 September 2010 05:33:00 pm Ambrose, Martin wrote:
> > On Wed, Sep 01, 2010 at 05:01:38, Caglar Akyuz wrote:
> > > On Tuesday 06 April 2010 12:54:59 am Ambrose, Martin wrote:
> > > > This work includes the following:
> > > > . Implement handler for FBIO_WAITFORVSYNC ioctl.
> > > >
> > > > . Allocate the data and palette buffers separately.
> > > > A consequence of this is that the palette and data loading is now
> > > > done in different phases. And that the LCD must be disabled
> > > > temporarily after the palette is loaded but this will only happen
> > > > once after init and each time the palette is changed. I think this
> > > > is OK.
> > > >
> > > > . Allocate two (ping and pong) framebuffers from memory.
> > > >
> > > > . Add pan_display handler which toggles the LCDC DMA registers between
> > > > the ping and pong buffers.
> > >
> > > Hello,
> > >
> > > This patch breaks driver for a VGA display. After reverting this patch,
> > > display works as expected. Do you have any idea what may be the cause?
> > > I'm testing it on L-138 based Hawkboard.
> >
> > What is the nature of the error? Does the driver fail to load/initialize?
> > Does the user space API still work but the display is corrupted? Something
> > else?
> >
> > Regards,
> > Martin
> >
>
> There is no error in log messages, but display is showing total garbage.
>
> I'm trying with framebuffer console but copying known patterns to fb0 also
> shows garbage. I prepared 3 raw images (red, green, blue) all having the same
> size as framebuffer. Then:
>
> $cp {red|green|blue} /dev/fb0
>
> shows garbage for all three.
>
> I compared hsync, vsync, pclk video signals with the working case and all are
> the same.
>
Hmm. I really have no idea what's wrong.
I've used the same code on with a DVI output patch (not in tree) which
works for me so I think the resolution portion should be ok.
There is a build control in the source drivers/video/da8xx-fb.c
#define LCD_NUM_BUFFERS 2
You could try changing this to 1 to see if there is a difference.
Although not sure how much information about the root cause this would generate.
I couldn't find reference to the Hawkboard in the mainline.
Is there a git repo which I could use as a remote to look at diffs?
Regards,
Martin
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