[PATCH 2/2 v2] eSDHC: Fix errors when booting kernel with fsl esdhc

[Zang Roy-R61911]

> -----Original Message-----
> From: linux-mmc-owner at vger.kernel.org [mailto:linux-mmc-owner at vger.kernel.org]
> On Behalf Of Anton Vorontsov
> Sent: Friday, July 22, 2011 18:15 PM
> To: Zang Roy-R61911
> Cc: linux-mmc at vger.kernel.org; linuxppc-dev at lists.ozlabs.org; akpm at linux-
> foundation.org; Xu Lei-B33228; Kumar Gala
> Subject: Re: [PATCH 2/2 v2] eSDHC: Fix errors when booting kernel with fsl esdhc
> 
> On Fri, Jul 22, 2011 at 06:15:17PM +0800, Roy Zang wrote:
> [...]
> >  	if (host->version >= SDHCI_SPEC_200) {
> > -		ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
> > -		ctrl &= ~SDHCI_CTRL_DMA_MASK;
> > -		if ((host->flags & SDHCI_REQ_USE_DMA) &&
> > -			(host->flags & SDHCI_USE_ADMA))
> > -			ctrl |= SDHCI_CTRL_ADMA32;
> > -		else
> > -			ctrl |= SDHCI_CTRL_SDMA;
> > -		sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
> > +		if (host->quirks & SDHCI_QUIRK_QORIQ_PROCTL_WEIRD) {
> > +#define ESDHCI_PROCTL_DMAS_MASK		0x00000300
> > +#define ESDHCI_PROCTL_ADMA32		0x00000200
> > +#define ESDHCI_PROCTL_SDMA		0x00000000
> > +			ctrl = sdhci_readl(host, SDHCI_HOST_CONTROL);
> > +			ctrl &= ~ESDHCI_PROCTL_DMAS_MASK;
> > +			if ((host->flags & SDHCI_REQ_USE_DMA) &&
> > +				(host->flags & SDHCI_USE_ADMA))
> > +				ctrl |= ESDHCI_PROCTL_ADMA32;
> > +			else
> > +				ctrl |= ESDHCI_PROCTL_SDMA;
> > +			sdhci_writel(host, ctrl, SDHCI_HOST_CONTROL);
> > +		} else {
> > +			ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
> > +			ctrl &= ~SDHCI_CTRL_DMA_MASK;
> > +			if ((host->flags & SDHCI_REQ_USE_DMA) &&
> > +				(host->flags & SDHCI_USE_ADMA))
> > +				ctrl |= SDHCI_CTRL_ADMA32;
> > +			else
> > +				ctrl |= SDHCI_CTRL_SDMA;
> > +			sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
> 
> We try to not pollute generic sdhci.c driver with chip-specific
> quirks.
> 
> Maybe you can do the fixups via IO accessors? Or by introducing
> some additional sdhci op?
Anton,
thanks for the comment, as we discussed, the original code use 8 bit byte operation,
while in fact, on some powerpc platform, 32 bit operation is needed. 
should it be possible fixed by adding some wrapper in IO accessors or introduce additional sdhci op?
Please advice more. 
Thanks.
Roy