From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mason Subject: Re: mmc0: Invalid maximum block size, assuming 512 bytes Date: Mon, 1 Feb 2016 22:32:16 +0100 Message-ID: <56AFCEE0.1090005@free.fr> References: <569E575A.5070401@free.fr> <569EE03F.9090008@rock-chips.com> <56A0F2A1.3060805@free.fr> <56A18EFE.6000900@rock-chips.com> <56A1D791.9010803@free.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Return-path: Received: from smtp4-g21.free.fr ([212.27.42.4]:44353 "EHLO smtp4-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752794AbcBAVcb (ORCPT ); Mon, 1 Feb 2016 16:32:31 -0500 In-Reply-To: <56A1D791.9010803@free.fr> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: linux-mmc Cc: Shawn Lin , Michal Simek , Soren Brinkmann , Suman Tripathi , Arnd Bergmann , Ulf Hansson , Sebastian Frias On 22/01/2016 08:17, Mason wrote: > On 22/01/2016 03:07, Shawn Lin wrote: > >> On 2016/1/21 23:00, Mason wrote: >> >>> So that means I have to write code in >>> drivers/mmc/host/sdhci-of-arasan.c correct? >> >> It depends. If you think 512 block size if okay for you, leave it alone. >> Otherwise, add it in drivers/mmc/host/sdhci-of-arasan.c :) > > When I measured the read/write throughput to an attached > SD card, I got around 16 MB/s, and I thought raising the > block size might help with throughput? > > I'll test and report back. Haven't had time to test yet, but I wanted to ask experienced folks what to expect when raising the block size from 512 to 2048 bytes? I don't think it would speed up dd'ing the entire device? (Especially if we use a large block size in dd.) Would it perhaps speed up myriads of random accesses? Regards.