| Message ID | 200902061653.12821.jpihet@mvista.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream, archived |
| Headers | show |
Jean Pihet wrote: > 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? > What about making use of a function like this: static void reset_host_controller(struct mmc_omap_host *host, unsigned bit) { unsigned long i, limit = loops_per_jiffy; OMAP_HSMMC_WRITE(host->base, SYSCTL, OMAP_HSMMC_READ(host->base, SYSCTL) | bit); for (i = 0; i < limit; i++) { if (!(OMAP_HSMMC_READ(host->base, SYSCTL) & bit)) return; cpu_relax(); } dev_err(mmc_dev(host->mmc), "%s: timeout waiting on software reset\n", mmc_hostname(host->mmc)); } And then just put: reset_host_controller(host, SRD); and reset_host_controller(host, SRC); in the right places. >> 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 <jpihet@mvista.com> > 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 <jpihet@mvista.com> > --- > 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 > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From 5ee867d09efe22a903ac7373a05e9e047bad6544 Mon Sep 17 00:00:00 2001 From: Jean Pihet <jpihet@mvista.com> 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 <jpihet@mvista.com> --- 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