[U-Boot] [PATCH] i.MX28: Enable SD DMA only if DCache enabled

[Marek Vasut]

Dear Fabio Estevam,

> On Wed, Apr 4, 2012 at 6:51 PM, Marek Vasut <marex at denx.de> wrote:
> > +/* Enable DMA transfers only if DCache is on. */
> > +#ifndef CONFIG_SYS_DCACHE_OFF
> > +#define CONFIG_MXS_MMC_DMA
> > +#endif
> 
> Your patch makes sense, but I would prefer not to couple
> CONFIG_MXS_MMC_DMA with DCACHE support.
> 
> Someone may want to enable cache, but still uses MMC driver in PIO mode.

You don't, it's slow as crap then.

> IMHO CONFIG_MXS_MMC_DMA could be defined in configs/board.h when needed.
> 
> Yesterday I was running MMC DMA without DCACHE support and it did work
> (after the mxs_dma_init changes).

I have some obscure card now and I'm seeing breakage (DMA transfer timeout).

btw. Fabio, can you ping me on jabber please?

Best regards,
Marek Vasut