From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753181AbYIYHGT (ORCPT ); Thu, 25 Sep 2008 03:06:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751655AbYIYHGH (ORCPT ); Thu, 25 Sep 2008 03:06:07 -0400 Received: from server.drzeus.cx ([85.8.24.28]:34108 "EHLO smtp.drzeus.cx" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751648AbYIYHGG (ORCPT ); Thu, 25 Sep 2008 03:06:06 -0400 Date: Thu, 25 Sep 2008 09:05:56 +0200 From: Pierre Ossman To: Haavard Skinnemoen Cc: kernel@avr32linux.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/4] atmel-mci: support multiple mmc slots Message-ID: <20080925090556.44940c89@mjolnir.drzeus.cx> In-Reply-To: <20080924163527.30cfc223@hskinnemo-gx745.norway.atmel.com> References: <1222101497-21183-1-git-send-email-haavard.skinnemoen@atmel.com> <1222101497-21183-2-git-send-email-haavard.skinnemoen@atmel.com> <1222101497-21183-3-git-send-email-haavard.skinnemoen@atmel.com> <1222101497-21183-4-git-send-email-haavard.skinnemoen@atmel.com> <20080923195342.52b1164d@mjolnir.drzeus.cx> <20080923201650.4525b883@hskinnemo-gx745.norway.atmel.com> <20080923211222.551389ab@mjolnir.drzeus.cx> <20080924163527.30cfc223@hskinnemo-gx745.norway.atmel.com> X-Mailer: Claws Mail 3.5.0cvs92 (GTK+ 2.14.0; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: multipart/signed; protocol="application/pgp-signature"; micalg=PGP-SHA1; boundary="=_freyr.drzeus.cx-8018-1222326363-0001-2" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a MIME-formatted message. If you see this text it means that your E-mail software does not support MIME-formatted messages. --=_freyr.drzeus.cx-8018-1222326363-0001-2 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Wed, 24 Sep 2008 16:35:27 +0200 Haavard Skinnemoen wrote: >=20 > On AP7000, the clock line is shared. Do I have to run the clock at the > minimum of the two slots' maximum rates, or does it only matter when > the card is being accessed? >=20 I'd say always. I'd never dare overclock something that's powered, even if we're not currently communicating with it. Remember to deal with the case of a powered but unclocked card. This will primarily happen during card init, but it could should up later as well if we start implementing aggressive power management. > > > > (This will also get a bit more painful when/if the core starts > > > > disabling the clock when a card is idle) > > >=20 > > > The atmel-mci driver already stops the clock between requests. > >=20 > > Then I expect a patch to remove that. Fiddling with the clock is > > dangerous and I've seen everything from hung cards to silently broken > > writes when you disable the clock too early after a request. >=20 > Ok. I'll see if I can fix that -- I take it you want a patch for > 2.6.27, then? >=20 .28 should be fine. It's a pretty uncommon bug. > > > >=20 > > > > Fall back to polling? > > >=20 > > > Probably, yes. Can I fall back to polling after the host has been > > > registered? > > >=20 > >=20 > > Hmm... no. Not sure how to handle this... >=20 > I'll see if I can figure out a way to do it. I'm not giving it high > priority since it's a fairly obscure error case which shouldn't happen > with properly implemented board code. >=20 Agreed. --=20 -- Pierre Ossman Linux kernel, MMC maintainer http://www.kernel.org rdesktop, core developer http://www.rdesktop.org WARNING: This correspondence is being monitored by the Swedish government. Make sure your server uses encryption for SMTP traffic and consider using PGP for end-to-end encryption. --=_freyr.drzeus.cx-8018-1222326363-0001-2 Content-Type: application/pgp-signature; name="signature.asc" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) iEYEARECAAYFAkjbOFkACgkQ7b8eESbyJLjaRQCg0p9cwc8uTOeoUMYk7zpHak+S +3UAniq/acLWCT6JzknkKN74wnbnz4fT =q2Zy -----END PGP SIGNATURE----- --=_freyr.drzeus.cx-8018-1222326363-0001-2--