Re: [PATCH 2/2] mmc: sdhci: Replace SDHCI_QUIRK_NO_MULTIBLOCK with a platform hook.

[Wolfram Sang <w.sang@pengutronix.de>]

On Sat, Feb 12, 2011 at 09:05:41PM +0000, Chris Ball wrote:

> > > If there still isn't a better alternative in mind, I'm thinking about
> > > going ahead and taking this patch, and then reusing the quirk bit for
> > > Chuanxiao's "mmc: set a suitable max_discard_sectors value for HC"
> > > patchset.
> > 
> > What about using the SZ_2048 quirk instead which could be done via
> > io-accessors?
> 
> That sounds fine too; I thought this one was more straightforward.
> 
> > That being said, I have a train travel tomorrow and will try to
> > see if a fixup() function would make sense for this one. Can you
> > wait one more day?
> 
> Sure, no immediate hurry.  Thanks!

So, I had a look today: Hmm....

I wanted something like a fixup-function called at the end of sdhci_add_host
which could handle all quirks doing some "mmc->..." changes. (I know that Olof
doesn't like this because it breaks abstraction. There might be a middle-way,
though.)

What bugs me with that approach is that it won't help against all quirks, so we
would need to replace all other quirks with functions, too. I'd think a
combination of QUIRKS and a fixup-function will be too confusing (we have that
to some degree already). Changing all at once is a major task though if you
want to group them properly and not do a 1:1 mapping.

I'd like to hear other people's opinion at this point. For now, my suggestion
would be to remove those quirks which could be handled via io-accessors. That
could be done on a step by step basis and should not create confusion if all
registers flaws are handled via io-accessors. But that's just my brainstorming,
so looking forward to comments.

Regards,

   Wolfram

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