Re: [PATCH] mmc: sdhci: change sdhci-pltfm into a module

[Shawn Guo]

Hi Grant,

On Fri, Jun 03, 2011 at 02:03:16PM -0600, Grant Likely wrote:
> On Thu, Jun 02, 2011 at 10:57:50AM +0800, Shawn Guo wrote:
> > From: Shawn Guo <shawn.guo@xxxxxxxxxxxxx>
> > 
> > There are a couple of problems left from the sdhci pltfm and OF
> > consolidation changes.
> > 
> > * When building more than one sdhci-pltfm based drivers in the same
> >   image, linker will give multiple definition error on the sdhci-pltfm
> >   helper functions.  For example right now, building sdhci-of-esdhc
> >   and sdhci-of-hlwd together is a valid combination from Kconfig view.
> > 
> > * With the current build method, there is error with building the
> >   drivers as module, but module installation fails with modprobe.
> > 
> > The patch fixes above problems by changing sdhci-pltfm into a module.
> > To avoid EXPORT_SYMBOL on so many big endian IO accessors, it moves
> > these accessors into sdhci-pltfm.h as the 'static inline' functions.
> > As a result, sdhci.h needs to be included in sdhci-pltfm.h, and in
> > turn can be removed from individual drivers which already include
> > sdhci-pltfm.h.
> 
> Mostly looks good.  One comment below about a static inline, but
> otherwise you can add my:
> 
> Acked-by: Grant Likely <grant.likely@xxxxxxxxxxxx>
> 
> > +static inline void sdhci_be32bs_writew(struct sdhci_host *host,
> > +				       u16 val, int reg)
> > +{
> > +	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > +	int base = reg & ~0x3;
> > +	int shift = (reg & 0x2) * 8;
> > +
> > +	switch (reg) {
> > +	case SDHCI_TRANSFER_MODE:
> > +		/*
> > +		 * Postpone this write, we must do it together with a
> > +		 * command write that is down below.
> > +		 */
> > +		pltfm_host->xfer_mode_shadow = val;
> > +		return;
> > +	case SDHCI_COMMAND:
> > +		sdhci_be32bs_writel(host,
> > +				    val << 16 | pltfm_host->xfer_mode_shadow,
> > +				    SDHCI_TRANSFER_MODE);
> > +		return;
> > +	}
> > +	clrsetbits_be32(host->ioaddr + base, 0xffff << shift, val << shift);
> > +}
> 
> This is really too big to be a static inline.  Go ahead and make it an
> exported symbol.  Personally, I wouldn't worry about it and just exporting all
> of these accessors.  Making them inline doesn't buy much anyway since
> they are used to initialize an ops table, and making them inline
> forces each driver to instantiate its own copy.
> 
Thanks for the comment.  Since Chris had picked the patch up, I would
not send another update for this, unless Chris asks me to do.  I
actually like to see all these accessors implemented in the same way
and in the same place.

-- 
Regards,
Shawn

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