Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753821AbaAQW7F (ORCPT ); Fri, 17 Jan 2014 17:59:05 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:5294 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752638AbaAQW7C convert rfc822-to-8bit (ORCPT ); Fri, 17 Jan 2014 17:59:02 -0500 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Fri, 17 Jan 2014 14:58:35 -0800 From: Philip Rakity To: Andrew Bresticker CC: Chris Ball , "linux-mmc@vger.kernel.org" , "linux-kernel@vger.kernel.org" Date: Fri, 17 Jan 2014 23:58:59 +0100 Subject: Re: [PATCH] mmc: sdhci: fix possible scheduling while atomic Thread-Topic: [PATCH] mmc: sdhci: fix possible scheduling while atomic Thread-Index: Ac8T17RxFYwwiyEwQ8SOKU6Ec2WTTQ== Message-ID: <0D8B1718-0A9D-467A-AFC5-108A868DE3BB@nvidia.com> References: <1389988630-9481-1-git-send-email-abrestic@chromium.org> In-Reply-To: <1389988630-9481-1-git-send-email-abrestic@chromium.org> Accept-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US MIME-Version: 1.0 Content-Language: en-US Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Jan 17, 2014, at 7:57 PM, Andrew Bresticker wrote: > sdhci_execute_tuning() takes host->lock without disabling interrupts. > Use spin_lock_irq{save,restore} instead so that we avoid taking an > interrupt and scheduling while holding host->lock. > > Signed-off-by: Andrew Bresticker > --- > drivers/mmc/host/sdhci.c | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > index ec3eb30..84c80e7 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -1857,12 +1857,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode) > unsigned long timeout; > int err = 0; > bool requires_tuning_nonuhs = false; > + unsigned long flags; > > host = mmc_priv(mmc); > > sdhci_runtime_pm_get(host); > disable_irq(host->irq); > - spin_lock(&host->lock); > + spin_lock_irqsave(&host->lock, flags); The disable_irq() call stops the controller from doing interrupts. Please explain what problem you are seeing > > ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); > > @@ -1882,14 +1883,14 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode) > requires_tuning_nonuhs) > ctrl |= SDHCI_CTRL_EXEC_TUNING; > else { > - spin_unlock(&host->lock); > + spin_unlock_irqrestore(&host->lock, flags); > enable_irq(host->irq); > sdhci_runtime_pm_put(host); > return 0; > } > > if (host->ops->platform_execute_tuning) { > - spin_unlock(&host->lock); > + spin_unlock_irqrestore(&host->lock, flags); > enable_irq(host->irq); > err = host->ops->platform_execute_tuning(host, opcode); > sdhci_runtime_pm_put(host); > @@ -1963,7 +1964,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode) > host->cmd = NULL; > host->mrq = NULL; > > - spin_unlock(&host->lock); > + spin_unlock_irqrestore(&host->lock, flags); > enable_irq(host->irq); > > /* Wait for Buffer Read Ready interrupt */ > @@ -1971,7 +1972,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode) > (host->tuning_done == 1), > msecs_to_jiffies(50)); > disable_irq(host->irq); > - spin_lock(&host->lock); > + spin_lock_irqsave(&host->lock, flags); > > if (!host->tuning_done) { > pr_info(DRIVER_NAME ": Timeout waiting for " > @@ -2046,7 +2047,7 @@ out: > err = 0; > > sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier); > - spin_unlock(&host->lock); > + spin_unlock_irqrestore(&host->lock, flags); > enable_irq(host->irq); > sdhci_runtime_pm_put(host); > > -- > 1.8.5.2 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/