From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: mmc: Add CONFIG_MMC_BLOCK_MAX_SPEED Date: Mon, 22 Feb 2016 07:45:52 +0100 Message-ID: <20160222064551.GA23884@amd> References: <1454617771-9842-1-git-send-email-salyzyn@android.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:51840 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752791AbcBVGpz (ORCPT ); Mon, 22 Feb 2016 01:45:55 -0500 Content-Disposition: inline In-Reply-To: <1454617771-9842-1-git-send-email-salyzyn@android.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Mark Salyzyn Cc: linux-kernel@vger.kernel.org, Ulf Hansson , Adrian Hunter , Andy Shevchenko , Luca Porzio , yalin wang , Shawn Lin , Jon Hunter , Grant Grundler , Yunpeng Gao , Chuanxiao Dong , linux-mmc@vger.kernel.org Hi! On Thu 2016-02-04 12:29:07, Mark Salyzyn wrote: > When CONFIG_MMC_BLOCK_MAX_SPEED is enabled, Expose max_read_speed, > max_write_speed and cache_size controls to simulate a slow eMMC device. > The boot default values for each respectively are > CONFIG_MMC_BLOCK_MAX_READ_SPEED, CONFIG_MMC_BLOCK_MAX_WRITE_SPEED and > CONFIG_MMC_BLOCK_CACHE_SIZE respectively; and if not defined are > 0 (off), 0, (off) and 4 MB also respectively. Extra , after 0. Dunno. At minimum, I'd call the option something like "MMC_DEBUG_MAX_SPEED" and the speeds should be really controlled via /sys or something... ...and ... is there reason to limit it to mmc devices? Making harddrive slow would make it useful for testing, too... ...and you have the /sys interface. Drop the config options? Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html