From patchwork Fri Feb 6 15:53:12 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean Pihet X-Patchwork-Id: 5899 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n16FrrxV023275 for ; Fri, 6 Feb 2009 15:53:53 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754513AbZBFPxi (ORCPT ); Fri, 6 Feb 2009 10:53:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756503AbZBFPxi (ORCPT ); Fri, 6 Feb 2009 10:53:38 -0500 Received: from gateway-1237.mvista.com ([63.81.120.158]:23551 "EHLO gateway-1237.mvista.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752995AbZBFPxg (ORCPT ); Fri, 6 Feb 2009 10:53:36 -0500 Received: from ip6-localhost (asshur.mvista.com [10.0.0.11]) by hermes.mvista.com (Postfix) with ESMTP id 8D25018D2B; Fri, 6 Feb 2009 07:53:32 -0800 (PST) From: Jean Pihet Organization: MontaVista To: Pierre Ossman Subject: [PATCH] OMAP: MMC: replace infinite loops with timeouts (was Re: [PATCH] OMAP: MMC: recover from transfer failures - Resend) Date: Fri, 6 Feb 2009 16:53:12 +0100 User-Agent: KMail/1.9.9 Cc: tony@atomide.com, Paul Walmsley , Andrew Morton , ext-adrian.hunter@nokia.com, linux-arm-kernel@lists.arm.linux.org.uk, linux-omap@vger.kernel.org, jarkko.lavinen@nokia.com, linux-kernel@vger.kernel.org References: <20081207213617.10456.43951.stgit@localhost> <200902061422.32689.jpihet@mvista.com> <20090206145343.2b8a5353@mjolnir.drzeus.cx> In-Reply-To: <20090206145343.2b8a5353@mjolnir.drzeus.cx> MIME-Version: 1.0 Message-Id: <200902061653.12821.jpihet@mvista.com> Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org Hi, > > > On Thu, 5 Feb 2009, Andrew Morton wrote: > > > > An infinite loop which assumes the hardware is perfect is always a > > > > worry. But I see the driver already does that, so we're no worse > > > > off.. > > > > Do you want a finite loop with udelay in it? I located 4 places were this > > could be used. If so I can generate a new patch for that. > > Even if Andrew doesn't, I'd sure like it. (the finite bit at least) :) Ok here is a patch that replaces the infinite loops with a timeout version. This patch applies on top of the previous one I sent ('[PATCH] OMAP: MMC: recover from transfer failures - Resend'). Is that OK? > Related, who is the maintainer of this driver? Tony? I'd like to have > someone who checks patches before I queue them up. > > > Rgds From 5ee867d09efe22a903ac7373a05e9e047bad6544 Mon Sep 17 00:00:00 2001 From: Jean Pihet Date: Fri, 6 Feb 2009 16:42:51 +0100 Subject: [PATCH] OMAP: MMC: replace infinite loops with timeouts Replace the 'while() ;' with a timeout Signed-off-by: Jean Pihet --- drivers/mmc/host/omap_hsmmc.c | 56 +++++++++++++++++++++++++++++++++-------- 1 files changed, 45 insertions(+), 11 deletions(-) SRC\n"); host->cmd->error = -ETIMEDOUT; } else { @@ -421,9 +432,17 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id) OMAP_HSMMC_WRITE(host->base, SYSCTL, OMAP_HSMMC_READ(host->base, SYSCTL) | SRD); - while (OMAP_HSMMC_READ(host->base, - SYSCTL) & SRD) - ; + timeout_counter = 0; + while ((OMAP_HSMMC_READ(host->base, + SYSCTL) & SRD) + && (timeout_counter++ < + MMC_TIMEOUT_WAIT_LOOPS)) + udelay(MMC_TIMEOUT_WAIT); + + if (OMAP_HSMMC_READ(host->base, + SYSCTL) & SRD) + dev_err(mmc_dev(host->mmc), + "Timeout waiting on SRD\n"); } } if ((status & DATA_TIMEOUT) || @@ -436,9 +455,17 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id) OMAP_HSMMC_WRITE(host->base, SYSCTL, OMAP_HSMMC_READ(host->base, SYSCTL) | SRD); - while (OMAP_HSMMC_READ(host->base, - SYSCTL) & SRD) - ; + timeout_counter = 0; + while ((OMAP_HSMMC_READ(host->base, + SYSCTL) & SRD) + && (timeout_counter++ < + MMC_TIMEOUT_WAIT_LOOPS)) + udelay(MMC_TIMEOUT_WAIT); + + if (OMAP_HSMMC_READ(host->base, + SYSCTL) & SRD) + dev_err(mmc_dev(host->mmc), + "Timeout waiting on SRD\n"); end_trans = 1; } } @@ -524,6 +551,7 @@ static void mmc_omap_detect(struct work_struct *work) { struct mmc_omap_host *host = container_of(work, struct mmc_omap_host, mmc_carddetect_work); + unsigned long timeout; sysfs_notify(&host->mmc->class_dev.kobj, NULL, "cover_switch"); if (host->carddetect) { @@ -531,8 +559,14 @@ static void mmc_omap_detect(struct work_struct *work) } else { OMAP_HSMMC_WRITE(host->base, SYSCTL, OMAP_HSMMC_READ(host->base, SYSCTL) | SRD); - while (OMAP_HSMMC_READ(host->base, SYSCTL) & SRD) - ; + /* Wait till the SRD bit is reset */ + timeout = jiffies + msecs_to_jiffies(MMC_TIMEOUT_MS); + while ((OMAP_HSMMC_READ(host->base, SYSCTL) & SRD) + && time_before(jiffies, timeout)) + msleep(1); + + if (OMAP_HSMMC_READ(host->base, SYSCTL) & SRD) + dev_err(mmc_dev(host->mmc), "Timeout waiting on SRD\n"); mmc_detect_change(host->mmc, (HZ * 50) / 1000); } -- 1.6.0.1.42.gf8c9c From 5ee867d09efe22a903ac7373a05e9e047bad6544 Mon Sep 17 00:00:00 2001 From: Jean Pihet Date: Fri, 6 Feb 2009 16:42:51 +0100 Subject: [PATCH] OMAP: MMC: replace infinite loops with timeouts Replace the 'while() ;' with a timeout Signed-off-by: Jean Pihet --- drivers/mmc/host/omap_hsmmc.c | 56 +++++++++++++++++++++++++++++++++-------- 1 files changed, 45 insertions(+), 11 deletions(-) diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index 1ac6918..7ddc77e 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -102,6 +102,8 @@ #define OMAP_MMC_DATADIR_READ 1 #define OMAP_MMC_DATADIR_WRITE 2 #define MMC_TIMEOUT_MS 20 +#define MMC_TIMEOUT_WAIT 100 /* Active wait duration, in usec */ +#define MMC_TIMEOUT_WAIT_LOOPS ((MMC_TIMEOUT_MS * 1000) / MMC_TIMEOUT_WAIT) #define OMAP_MMC_MASTER_CLOCK 96000000 #define DRIVER_NAME "mmci-omap-hs" @@ -384,6 +386,7 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id) struct mmc_omap_host *host = dev_id; struct mmc_data *data; int end_cmd = 0, end_trans = 0, status; + unsigned long timeout_counter; if (host->cmd == NULL && host->data == NULL) { OMAP_HSMMC_WRITE(host->base, STAT, @@ -406,9 +409,17 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id) OMAP_HSMMC_WRITE(host->base, SYSCTL, OMAP_HSMMC_READ(host->base, SYSCTL) | SRC); - while (OMAP_HSMMC_READ(host->base, - SYSCTL) & SRC) - ; + timeout_counter = 0; + while ((OMAP_HSMMC_READ(host->base, + SYSCTL) & SRC) + && (timeout_counter++ < + MMC_TIMEOUT_WAIT_LOOPS)) + udelay(MMC_TIMEOUT_WAIT); + + if (OMAP_HSMMC_READ(host->base, + SYSCTL) & SRC) + dev_err(mmc_dev(host->mmc), + "Timeout waiting on SRC\n"); host->cmd->error = -ETIMEDOUT; } else { @@ -421,9 +432,17 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id) OMAP_HSMMC_WRITE(host->base, SYSCTL, OMAP_HSMMC_READ(host->base, SYSCTL) | SRD); - while (OMAP_HSMMC_READ(host->base, - SYSCTL) & SRD) - ; + timeout_counter = 0; + while ((OMAP_HSMMC_READ(host->base, + SYSCTL) & SRD) + && (timeout_counter++ < + MMC_TIMEOUT_WAIT_LOOPS)) + udelay(MMC_TIMEOUT_WAIT); + + if (OMAP_HSMMC_READ(host->base, + SYSCTL) & SRD) + dev_err(mmc_dev(host->mmc), + "Timeout waiting on SRD\n"); } } if ((status & DATA_TIMEOUT) || @@ -436,9 +455,17 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id) OMAP_HSMMC_WRITE(host->base, SYSCTL, OMAP_HSMMC_READ(host->base, SYSCTL) | SRD); - while (OMAP_HSMMC_READ(host->base, - SYSCTL) & SRD) - ; + timeout_counter = 0; + while ((OMAP_HSMMC_READ(host->base, + SYSCTL) & SRD) + && (timeout_counter++ < + MMC_TIMEOUT_WAIT_LOOPS)) + udelay(MMC_TIMEOUT_WAIT); + + if (OMAP_HSMMC_READ(host->base, + SYSCTL) & SRD) + dev_err(mmc_dev(host->mmc), + "Timeout waiting on SRD\n"); end_trans = 1; } } @@ -524,6 +551,7 @@ static void mmc_omap_detect(struct work_struct *work) { struct mmc_omap_host *host = container_of(work, struct mmc_omap_host, mmc_carddetect_work); + unsigned long timeout; sysfs_notify(&host->mmc->class_dev.kobj, NULL, "cover_switch"); if (host->carddetect) { @@ -531,8 +559,14 @@ static void mmc_omap_detect(struct work_struct *work) } else { OMAP_HSMMC_WRITE(host->base, SYSCTL, OMAP_HSMMC_READ(host->base, SYSCTL) | SRD); - while (OMAP_HSMMC_READ(host->base, SYSCTL) & SRD) - ; + /* Wait till the SRD bit is reset */ + timeout = jiffies + msecs_to_jiffies(MMC_TIMEOUT_MS); + while ((OMAP_HSMMC_READ(host->base, SYSCTL) & SRD) + && time_before(jiffies, timeout)) + msleep(1); + + if (OMAP_HSMMC_READ(host->base, SYSCTL) & SRD) + dev_err(mmc_dev(host->mmc), "Timeout waiting on SRD\n"); mmc_detect_change(host->mmc, (HZ * 50) / 1000); } -- 1.6.0.1.42.gf8c9c