cleaning up sdhci? (was Re: [RFC] thoughts about recent Samsung related patches)

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

[-- Attachment #1: Type: text/plain, Size: 1998 bytes --]

On Tue, Sep 14, 2010 at 09:05:30AM +0900, Kyungmin Park wrote:
> On Mon, Sep 13, 2010 at 9:31 PM, Wolfram Sang <w.sang@pengutronix.de> wrote:
> >> > I hope my comments are applicable; because there is no freely available
> >> > datasheet, I can't verify all of my assumptions. Looking forward to
> >> > comments.
> >> Good, I think it's possible. I'll try and send a patch.
> >
> > Any news on this ?
> 
> I tried and no problem to work, but I'm thinking does it really
> required for reducing one quirk?
> With this change sdhci-s3c should use the
> CONFIG_MMC_SDHCI_IO_ACCESSORS and it introduces the io functions for
> every io access.
> 
> So I'm not sure these change is required for s3c sdhci.
> 
> Give you opinions.

I know what you mean. Still, I'd prefer to see that sdhci.c implements
stuff as generic as possible and trying to follow the standard closely.
Exceptions to that should be handled elsewhere if possible. That is, if
some implementations of a controller do not adhere to that standard and
change some bits in the register layout, well, then they have to live
with the quirks and their performance issues IMHO.

BTW it is not only the HI_SPD issue, which is a candidate for the io-
accessors. I am also interested to get the 8BITBUS patch reverted. It
breaks some SD cards on some boards using the esdhc controller :(
Support for a 8bit-bus needs a bit more thought, it seems...

Seeing Alan's patchset, it seems to be a good time to do some
sdhci-cleanup. My impression is that we could get generalize a few
quirks by using io-accessors and overriding capabilties-flags. I am open
for other opinions, though. All in all, it would be great if we all
could combine our efforts and get some kind of master-plan :)
Will take a look at Alan's patches now...

Regards,

   Wolfram

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 198 bytes --]