From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philip Langdale Subject: Re: [PATCH] sdio: add MMC_CAP_VDD_165_195 host capability Date: Sat, 10 Oct 2009 11:42:15 -0700 Message-ID: <20091010114215.5f9d8c94@fido2.homeip.net> References: <1254160269.10634.15.camel@localhost> <4AC0FBF0.6090007@csr.com> <20090928192548.11da5c3c@fido2.homeip.net> <20090929202833.179fb521@mjolnir.ossman.eu> <20090929233732.62f470e0@mjolnir.ossman.eu> <20090929231013.5d67b36a@fido2.homeip.net> <20091008203826.5e027347@mjolnir.ossman.eu> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/LAHBbCSByOM9OlEoTHz5HYY"; protocol="application/pgp-signature" Return-path: Received: from usul.overt.org ([204.11.33.43]:52823 "EHLO usul.overt.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932948AbZJJSnW (ORCPT ); Sat, 10 Oct 2009 14:43:22 -0400 In-Reply-To: <20091008203826.5e027347@mjolnir.ossman.eu> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Pierre Ossman Cc: David Vrabel , Ohad Ben-Cohen , akpm@linux-foundation.org, ian@mnementh.co.uk, matt@console-pimps.org, roberto.foglietta@gmail.com, linux-mmc@vger.kernel.org --Sig_/LAHBbCSByOM9OlEoTHz5HYY Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Thu, 8 Oct 2009 20:38:26 +0200 Pierre Ossman wrote: > >=20 > > In practice, I expect that the timings are close enough that this > > will work anyway, but I think the situation is analogous to HS-MMC > > vs HS-SD. There the timings are slightly different and you felt it > > was enough to justify a separate host cap for each one. > >=20 >=20 > It's difficult to say without seeing the spec. But if things are not > backwards compatible, then we should probably add either a new timing > mode, or a new bus mode (where we have open drain and push pull > today). >=20 > > In fact, thinking about it in those terms, it suggests we need to > > retroactively introduce a reduced-voltage MMC host flag too, just in > > case SDHCI 3.0 controllers barf on those cards... > >=20 >=20 > Maybe. Again, it's difficult to say without seeing the specifics of > the new specification. Make sense. So, I guess the question is do we assume the best case (in which case there is no additional work to do - the code that is now in allows low voltage SDIO cards to try and run) or the worst case and add pre-emptive mode flags? David, you've actually seen the new spec right? What's your opinion? --phil --Sig_/LAHBbCSByOM9OlEoTHz5HYY Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkrQ1YcACgkQ+NaxlGp1aC4YswCgi76PnDQku9qQ/2/N6upk4EEX bgkAn2otlDK4nv0dDzxHO7ZjVuHIA1PN =EkzT -----END PGP SIGNATURE----- --Sig_/LAHBbCSByOM9OlEoTHz5HYY--