Re: [PATCH 1/5] arm/dt: tegra: Remove /memreserve/ from device-tree files

[Olof Johansson <olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org>]

On Tue, Nov 22, 2011 at 08:25:03AM -0800, Stephen Warren wrote:
> Marc Dietrich wrote at Tuesday, November 22, 2011 3:42 AM:
> > On Monday 21 November 2011 14:44:07 Stephen Warren wrote:
> > > There are no drivers in the kernel at present which can make use of the
> > > memory reserved by /memreserve/, so there is no point reserving it. Remove
> > > /memreserve/ to allow the user more memory. It's also unclear whether any
> > > future driver would actually require /memreserve/, or allocate memory
> > > through some other mechanism.
> > 
> > while this gives 512 MB of usable memory on my AC100, it causes some funny
> > pictures on the screen ;-) I guess our bootloader (fastboot) already setups
> > the frambuffer there (and enables the backlight). I guess it shouldn't be
> > harmful as nothing else writes to this memory area. Otherwise you may add that
> > the bootloader (or the kernel cmdline supplied by the bootloader) is now
> > responsible for the reservation to the description.
> 
> Ah yes, I guess that would happen. I'm only testing with mainline U-Boot...
> 
> I'd suggest this is acceptable fallout for now; I don't believe it will
> cause any active problems, and as you say, you can get the bootloader to
> set a command-line that excludes the frame-buffer if you want to solve
> this. Do you agree?

Agreed. It would make more sense to teach u-boot to reserve the memory.


-Olof