From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Poirier Subject: Re: SDHC card affected by preemption model in 2.6.35 Date: Tue, 15 Jun 2010 15:17:13 -0600 Message-ID: <1276636633.2824.88.camel@black> References: <1276613548.2824.46.camel@black> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from adelie.canonical.com ([91.189.90.139]:39075 "EHLO adelie.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754659Ab0FOVRF (ORCPT ); Tue, 15 Jun 2010 17:17:05 -0400 In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Venkatraman S Cc: linux-omap@vger.kernel.org On Tue, 2010-06-15 at 20:58 +0530, Venkatraman S wrote: > Mathieu Poirier wrote: > > HW: Beagleboard rev. C2 and C4 > > Processor: OMAP3 > > Kernel: 2.6.35-rc2 > > Driver: mmci-omap-hs > > > > I am faced with an SDHC card problem on a beagleboard. Some cards > > cannot be initialized on startup while others work perfectly. I tracked > > the issue down to one single kernel config: PREEMPT_VOLUNTARY. > > > > When going from PREEMPT_VOLUNTARY to PREEMPT_NONE the problem goes away. > > > > When booting, a failing card (PREEMPT_VOLUNTARY) will output the > > following: > > [ 2.283355] mmc0: error -110 whilst initialising SD card > > > > I have also seen transfer errors such as this one: > > [ 105.343780] mmcblk0: error -110 transferring data, sector 798431, nr > > 26, card status 0xc00 > > > > When working properly (PREEMPT_NONE), you get: > > [ 27.026519] mmc0: new high speed SDHC card at address 0007 > > [ 27.075775] mmcblk0: mmc0:0007 SD08G 7.49 GiB > > > > We seem to have a little timing problem - has anyone seen the same > > issue ? Can driver "mmci-omap-hs" actually work under > > PREEMPT_VOLUNTARY ? > > > > Thanks, Mathieu. > > > > I will check this out - not tested with PREEMPT_VOLUNTARY so far. > If it's not too much trouble, can you provide a log with CONFIG_MMC_DEBUG ? > Also, some details about the failing card would be helpful. > > Thanks, > Venkat. Venkat, Unfortunately enabling CONFIG_MMC_DEBUG doesn't yield more information - the error message is the same and no additional output shows on the console. As for the cards, had failures with 3 different manufacturer: - Patriot Memory, MicroSD card, 8GB, class 4, SDHC. - Kinston, 4GB, class 6, SDHC. - Sandisk, 4GB, Class 2, SDHC. I am more than willing to test kernels for you if need be. Thanks, Mathieu.