From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Ball Subject: Re: [PATCH] SD/MMC: fix the issue of SDHC performance regression Date: Mon, 07 Nov 2011 08:20:10 -0500 Message-ID: References: <1320658589-13143-1-git-send-email-b32616@freescale.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from void.printf.net ([89.145.121.20]:57947 "EHLO void.printf.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754377Ab1KGNUR (ORCPT ); Mon, 7 Nov 2011 08:20:17 -0500 In-Reply-To: <1320658589-13143-1-git-send-email-b32616@freescale.com> (Qiang Liu's message of "Mon, 7 Nov 2011 17:36:29 +0800") Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Qiang Liu Cc: linux-mmc@vger.kernel.org, leoli@freescale.com, kumar.gala@freescale.com Hi, On Mon, Nov 07 2011, Qiang Liu wrote: > Low performance of SDHC (half of before) due to its frequency was set to 25MHz, > but not 50MHz (involved by commit id 013909c4ffd16ded4895528b856fd8782df04dc6, > add support for query function modes for uhs cards according to Physical Layer > SPEC V3.01). > > Set high speed max frequency according to response status of CMD6, but > not for SPEC Version. Response of switch command is first consideration > factor when set SDHC max working frequency. TRAN_SPEED in CSD register > will be seemed as the second factor. > > Signed-off-by: Qiang Liu Have you seen: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=f2815f68dabbb373fd1c9f0fd4a609d486697c2b ("mmc: sd: Handle SD3.0 cards not supporting UHS-I bus speed mode") which is already in mainline? I think your patch is identical. Thanks, - Chris. -- Chris Ball One Laptop Per Child