Re: ioremap on system memory

From: Marcus Folkesson
Date: Fri Nov 11 2011 - 01:59:20 EST


2011/11/10 Ryan Mallon <rmallon@xxxxxxxxx>
>
> On 10/11/11 19:06, Marcus Folkesson wrote:
>
> > Hi,
> >
> > I'm working with a custom based platform based on OMAP-L138.
> > A driver we are using is ioremapping system memory. It does this to
> > share data between the GPP and DSP core.
> > This is not allowed in later kernel versions since ARMv6+ does not support this.
> >
> > Is there any good(and easy) way to get around this or is it so
> > fundamentally wrong that the driver should be written from scratch?
>
>
> Cc'ed the ARM kernel list and Marek Szyprowski (CMA developer). The CMA
> patches I think do what you want, but I am not sure if they are merged
> yet. The other solution (again, I'm not an expert on this area) is to
> not pass the region of memory you want to manage as part of Linux's
> normal system memory. See how the OMAP framebuffer driver reserves a
> region of SDRAM (arch/arm/plat-omap/fb.c).
>
> Some one else on the ARM list can probably explain in more detail.
>
> ~Ryan
>

Not passing the region of the concerned memory seems to solve the problem.
Thank you!

Med vänliga hälsningar / Best regards
Marcus Folkesson
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