From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751153Ab1GRVFm (ORCPT ); Mon, 18 Jul 2011 17:05:42 -0400 Received: from void.printf.net ([89.145.121.20]:40406 "EHLO void.printf.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750954Ab1GRVFk (ORCPT ); Mon, 18 Jul 2011 17:05:40 -0400 From: Chris Ball To: Manoj Iyer Cc: Arnd Bergmann , linux-kernel@vger.kernel.org, jbarnes@virtuousgeek.org, matsumur@nts.ricoh.co.jp, linux-pci@vger.kernel.org, linux-mmc@vger.kernel.org Subject: Re: [PATCH] mmc: Added quirks for Ricoh 1180:e823 lower base clock frequency References: <1310419715-13254-1-git-send-email-manoj.iyer@canonical.com> <201107131835.25217.arnd@arndb.de> Date: Mon, 18 Jul 2011 17:05:32 -0400 In-Reply-To: (Manoj Iyer's message of "Mon, 18 Jul 2011 15:47:33 -0500 (CDT)") Message-ID: User-Agent: Gnus/5.110018 (No Gnus v0.18) Emacs/23.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Manoj, On Mon, Jul 18 2011, Manoj Iyer wrote: > Right, without the patch I get.. > > [ 52.526665] mmc0: new SDHC card at address e624 > [ 52.571228] mmcblk0: mmc0:e624 SD16G 14.8 GiB > [ 52.591071] mmcblk0: retrying using single block read > [ 52.593105] mmcblk0: error -84 transferring data, sector 0, nr 8, > card status 0x900 > [ 52.593109] end_request: I/O error, dev mmcblk0, sector 0 > [ 52.594594] mmcblk0: error -84 transferring data, sector 1, nr 7, > card status 0x900 > [ 52.594604] end_request: I/O error, dev mmcblk0, sector 1 > [ 52.602893] quiet_error: 24 callbacks suppressed > [ 52.602902] Buffer I/O error on device mmcblk0, logical block 0 > [ 52.605349] ldm_validate_partition_table(): Disk read failed. > [ 52.605384] Dev mmcblk0: unable to read RDB block 0 > [ 52.607729] mmcblk0: unable to read partition table > u@u:~$ > > So, I cannot generate any comparison data with this SD card. I see, thanks. So we're lacking any data on what speed the card would normally provide. Perhaps you could try that card on a different controller, just so we're able to see whether it's usually possible to get closer to 45M/sec with it? I think I'll take your patch as-is for 3.1 -- since if there is a performance degradation, it's on cards that simply don't work at all right now -- and if you're able to work on a followup patch that only performs the clock-lowering after the first error, I think that'd be a handy patch to have around. Does that sound good? Thanks! - Chris. -- Chris Ball One Laptop Per Child