OMAP4430 SDP boot issues.. (Was Re: OMAP2430 SDP boot broken after Linus' rmk merge)

Russell King - ARM Linux linux at arm.linux.org.uk
Wed Jul 24 13:23:22 EDT 2013


On Wed, Jul 24, 2013 at 11:40:33AM -0400, Santosh Shilimkar wrote:
> On Wednesday 24 July 2013 10:52 AM, Russell King - ARM Linux wrote:
> > I also continue to be disappointed by the lack of things working on the
> > 4430 - it's been a number of years now and _still_ the on-board LCDs do
> > not work.  People have tried to blame that on hardware faults and the
> > like, but they're just being idiotic when they say stuff like that.  It
> > can't be hardware faults when the kernel supplied with the board is able
> > to make them work to the extent that userspace can play back video on all
> > three output devices simultaneously, without hiccup or any imperfection.
> > I don't know whether it's just that the backlight support isn't working
> > or what - because any information on the 4430 seems to be a tightly
> > controlled secret that only a few select people are permitted to know
> > about.  As far as I'm concerned, much of the hardware is a black box to
> > me.
> > 
> On the display related issues, Tomi and Archit have been sorting out
> issue but am not sure about the current state. If the pre-built binaries
> video playback works means your hardware seems to be fine.

Just let me be absolutely crystal clear about this: the on-board LCDs
have _never_ worked with a mainline kernel, but they did work with the
kernel which originally came with the board with the original 4430 SoC.
I can right now put the original 4430 SoC back on the board and boot
using the kernel which is still on the SD card and they will work.

Even with the original 4430 SoC and mainline kernels, they have never
worked.

I tried it back and forth several times, but even with this, the
explanation was always "your hardware must be faulty".  And then the wrong
voltage levels was found which was preventing the LCD modules from even
being recognised... but still, no sign of life on the LCD panels.

It may be that there's some error in the kernel configuration I'm building.
I don't know, because I have _no_ idea what hardware is involved in
bringing the LCDs online.  Like I said above, the 4430SDP board is just
a black box.  I am totally reliant on others telling me what the right
config options are supposed to be and fixing problems when things don't
work.

With the lack of information on this board, all I can do when things don't
work is whinge and moan at people.  I am powerless to debug the problems
myself, even if they're a simple misconfiguration.

Is there information available on the 4430SDP?  Is there any reason I
can't have access to it?



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