From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Poirier Subject: SDHC card affected by preemption model in 2.6.35 Date: Tue, 15 Jun 2010 08:52:28 -0600 Message-ID: <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]:44428 "EHLO adelie.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757906Ab0FOOwR (ORCPT ); Tue, 15 Jun 2010 10:52:17 -0400 Received: from hutte.canonical.com ([91.189.90.181]) by adelie.canonical.com with esmtp (Exim 4.69 #1 (Debian)) id 1OOXUv-0003BT-6m for ; Tue, 15 Jun 2010 15:52:17 +0100 Received: from s0106002369de4dac.cg.shawcable.net ([70.73.24.112] helo=[192.168.1.103]) by hutte.canonical.com with esmtpsa (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.69) (envelope-from ) id 1OOXUu-0008Mq-Rk for linux-omap@vger.kernel.org; Tue, 15 Jun 2010 15:52:17 +0100 Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: linux-omap@vger.kernel.org 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.