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

Marek Vasut marex at denx.de
Tue Sep 18 21:36:18 CEST 2012

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?

> 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.

> > > This is by no means Tegra specific. In fact every board that has proper
> > > cache invalidation support should expose this problem.
> > 
> > Yea of course, the arm926ejs had this trouble too, see the mxs MMC driver
> > and arm926 cache.c
> I suppose we could do something like this as well. If we make sure that
> the buffer is properly aligned and and sized, we could pass the aligned
> end address to invalidate_dcache_range().
> Thierry

Best regards,
Marek Vasut

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