[U-Boot] Cache alignment warnings on Tegra (ARM)

[Marek Vasut]

Dear Thierry Reding,

> On Tue, Sep 18, 2012 at 09:36:18PM +0200, Marek Vasut wrote:
> > Dear Thierry Reding,
> > 
> > [...]
> > 
> > > > Sure, but after you apply the bounce buffer, you can safely
> > > > invalidate the whole cacheline, so align it up and be done with it.
> > > 
> > > That's what I proposed to do last time around but it was NAK'ed.
> > 
> > By who?
> 
> I think it was Simon Glass and Mike Frysinger. They NAK'ed it for very
> valid reason, so I'm not complaining.
> 
> > > At the
> > > time I didn't ensure that the buffer was actually big enough, which is
> > > why people didn't like it (data on the stack after the DMA buffer might
> > > be invalidated as well).
> > 
> > Correct, thus the bounce buffer.
> 
> I don't think we even need the bounce buffer. All that needs to be done
> is guarantee that the buffers passed to the MMC driver are properly
> aligned and sized.

If you resize the MMC structures and call sizeof() on them to get the size of 
the transfer, the MMC won't work correctly anymore.

> Thierry

Best regards,
Marek Vasut