From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 746DFC43387 for ; Tue, 18 Dec 2018 16:44:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 450B221873 for ; Tue, 18 Dec 2018 16:44:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545151451; bh=40HQvD5gtbJ5c7qycQ2+xgh0rBixMUc+dX842omhrrk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SHbMEw2E5pay8sajKxpkpCE/TrrI5gsVPNbhvvbWCAtMSFinoQrX+QSkhcenS9qw/ 2EpzKKgs0A0xbzpynk/6hvlCVS/hLj+X4y8cO8xzyvksgS9zK5ByVZ7WSuaZ8tCy5S 8GJcvpxG+oyJgcsVxupOFMDgzKfD+xQXU2hjOwLU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727311AbeLRQkh (ORCPT ); Tue, 18 Dec 2018 11:40:37 -0500 Received: from mail.kernel.org ([198.145.29.99]:37696 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727153AbeLRQkf (ORCPT ); Tue, 18 Dec 2018 11:40:35 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B0387218A5; Tue, 18 Dec 2018 16:40:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545151234; bh=40HQvD5gtbJ5c7qycQ2+xgh0rBixMUc+dX842omhrrk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mYDJqJhSOg6walClAGmcwERfp0QM8o9dBy4tW8CMv2gTYvoYY8YtMKxPYxeOauieq B+o1qOucQnxO71kTq56WjdE6mvA1fslZwPdCRXYGdGjKZA7HyOXfoiXqNIBvYG+bAn 0F2XHO/Ug2VGdDiE0+jpnx3wBcLhjjymyIofaNcc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alek Du , Adrian Hunter , Ulf Hansson Subject: [PATCH 4.19 20/44] mmc: sdhci: fix the timeout check window for clock and reset Date: Tue, 18 Dec 2018 17:39:32 +0100 Message-Id: <20181218163929.871016709@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20181218163927.119623235@linuxfoundation.org> References: <20181218163927.119623235@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alek Du commit b704441e38f645dcfba1348ca3cc1ba43d1a9f31 upstream. We observed some premature timeouts on a virtualization platform, the log is like this: case 1: [159525.255629] mmc1: Internal clock never stabilised. [159525.255818] mmc1: sdhci: ============ SDHCI REGISTER DUMP =========== [159525.256049] mmc1: sdhci: Sys addr: 0x00000000 | Version: 0x00001002 ... [159525.257205] mmc1: sdhci: Wake-up: 0x00000000 | Clock: 0x0000fa03 >>From the clock control register dump, we are pretty sure the clock was stablized. case 2: [ 914.550127] mmc1: Reset 0x2 never completed. [ 914.550321] mmc1: sdhci: ============ SDHCI REGISTER DUMP =========== [ 914.550608] mmc1: sdhci: Sys addr: 0x00000010 | Version: 0x00001002 After checking the sdhci code, we found the timeout check actually has a little window that the CPU can be scheduled out and when it comes back, the original time set or check is not valid. Fixes: 5a436cc0af62 ("mmc: sdhci: Optimize delay loops") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Alek Du Acked-by: Adrian Hunter Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman --- drivers/mmc/host/sdhci.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -193,8 +193,12 @@ void sdhci_reset(struct sdhci_host *host timeout = ktime_add_ms(ktime_get(), 100); /* hw clears the bit when it's done */ - while (sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask) { - if (ktime_after(ktime_get(), timeout)) { + while (1) { + bool timedout = ktime_after(ktime_get(), timeout); + + if (!(sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask)) + break; + if (timedout) { pr_err("%s: Reset 0x%x never completed.\n", mmc_hostname(host->mmc), (int)mask); sdhci_dumpregs(host); @@ -1495,9 +1499,13 @@ void sdhci_enable_clk(struct sdhci_host /* Wait max 20 ms */ timeout = ktime_add_ms(ktime_get(), 20); - while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL)) - & SDHCI_CLOCK_INT_STABLE)) { - if (ktime_after(ktime_get(), timeout)) { + while (1) { + bool timedout = ktime_after(ktime_get(), timeout); + + clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL); + if (clk & SDHCI_CLOCK_INT_STABLE) + break; + if (timedout) { pr_err("%s: Internal clock never stabilised.\n", mmc_hostname(host->mmc)); sdhci_dumpregs(host);