[U-Boot] [PATCH] i.MX28: Add function to adjust memory parameters

Marek Vasut marex at denx.de
Mon Jun 18 17:43:58 CEST 2012


Dear Stefano Babic,

> > On 18/06/2012 16:23, Marek Vasut wrote:
> > > Dear Fabio Estevam,
> > > 
> > >> Hi Marek,
> > >> 
> > >> On Thu, May 31, 2012 at 3:45 PM, Marek Vasut <marex at denx.de> wrote:
> > >>> Call this or similar in your spl_boot.c to adjust the DRAM
> > >>> configuration. Actually I think even the following value should fix
> > >>> your problem:
> > >>> 
> > >>> void mx28_adjust_memory_params(uint32_t *dram_vals)
> > >>> {
> > >>> 
> > >>>        dram_vals[0x74 >> 2] = 0x0f02010a;
> > >>> 
> > >>> }
> > >> 
> > >> I finally had a chance to try this and my mx28evk can boot again with
> > >> your patch + the code above.
> > >> 
> > >> How do we handle this? Would you send a v2 with this additional code
> > >> or should I do it myself after your original patch in this thread gets
> > >> applied?
> > > 
> > > Stefano, can you please apply this? So Fabio can apply his on top of
> > > it?
> > 
> > I do it.
> > 
> > >> Also, please explain to the mortal folks what 'dram_vals[0x74 >> 2] =
> > >> 0x0f02010a;' means.
> > > 
> > > Well, check that particular register (memory configuration register at
> > > +0x74 offset) in the datasheet. It's basically adjusting the number of
> > > enabled address row and columns.
> > > 
> > >> It is not something very trivial to figure out :-)
> > > 
> > > It actually is, see above ;-)
> > 
> > I see, but I will never apply a patch programmed in hexadecimal instead
> > of plain C ;-)
> 
> So ... what do you expect me to do? The register is called HW_DRAM_CTL29
> (very descriptive) ... do you want me to create a file full of
> HW_DRAM_CTLnn ?

Would adding such comment be enough to satisfy you? (In slightly more polite 
manner I mean ... damn I'm loosing it, 2 days until exam :'-( ). Sorry for being 
rough, Stefano.

> > Stefano

Best regards,
Marek Vasut


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