From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: cleaning up sdhci? (was Re: [RFC] thoughts about recent Samsung related patches) Date: Tue, 14 Sep 2010 12:28:59 +0200 Message-ID: <20100914102858.GB2629@pengutronix.de> References: <20100906110059.GC2617@pengutronix.de> <20100913123108.GA5497@pengutronix.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="+pHx0qQiF2pBVqBT" Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:37250 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752113Ab0INK3E (ORCPT ); Tue, 14 Sep 2010 06:29:04 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Kyungmin Park Cc: linux-mmc@vger.kernel.org, pierre-list@ossman.eu, gdavis@mvista.com, cbouatmailru@gmail.com, m.szyprowski@samsung.com, akpm@linux-foundation.org, =?utf-8?B?7KCV7J6s7ZuI?= , Alan Cox --+pHx0qQiF2pBVqBT Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Sep 14, 2010 at 09:05:30AM +0900, Kyungmin Park wrote: > On Mon, Sep 13, 2010 at 9:31 PM, Wolfram Sang wro= te: > >> > I hope my comments are applicable; because there is no freely availa= ble > >> > 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 ? >=20 > 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. >=20 > So I'm not sure these change is required for s3c sdhci. >=20 > 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 --=20 Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ | --+pHx0qQiF2pBVqBT Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iEYEARECAAYFAkyPTmoACgkQD27XaX1/VRuFiQCgqGY/t0It90WKf221n1OIjeVQ rRUAn3Bv/izjSwXsgyKW/V5Bu6b+z3wV =zAHh -----END PGP SIGNATURE----- --+pHx0qQiF2pBVqBT--