Dear Ulf, On Fri, 23 Jan 2015 00:23:29 -0800 Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > On 21 January 2015 at 13:45, Jisheng Zhang <jszhang@xxxxxxxxxxx> wrote: > > This patch is to fix a race condition that may cause an unhandled irq, > > which results in big sdhci interrupt numbers and endless "mmc1: got irq > > while runtime suspended" msgs before v3.15. > > > > Consider following scenario: > > > > CPU0 CPU1 > > sdhci_pxav3_runtime_suspend() > > spin_lock_irqsave(&host->lock, flags); > > sdhci_irq() > > spining on the &host->lock > > host->runtime_suspended = true; > > spin_unlock_irqrestore(&host->lock, flags); > > get the &host->lock > > runtime_suspended is true now > > return IRQ_NONE; > > > > Fix this race by using the core sdhci.c supplied > > sdhci_runtime_suspend_host() in runtime suspend hook which will disable > > card interrupts. We also use the sdhci_runtime_resume_host() in the > > runtime resume hook accordingly. > > > > Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx> > > Cc: <stable@xxxxxxxxxxxxxxx> # v3.9+ > > --- > > drivers/mmc/host/sdhci-pxav3.c | 15 ++++----------- > > 1 file changed, 4 insertions(+), 11 deletions(-) > > > > diff --git a/drivers/mmc/host/sdhci-pxav3.c > > b/drivers/mmc/host/sdhci-pxav3.c index 4de39fb..6975c51 100644 > > --- a/drivers/mmc/host/sdhci-pxav3.c > > +++ b/drivers/mmc/host/sdhci-pxav3.c > > @@ -460,17 +460,15 @@ static int sdhci_pxav3_runtime_suspend(struct > > device *dev) struct sdhci_host *host = dev_get_drvdata(dev); > > struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); > > struct sdhci_pxa *pxa = pltfm_host->priv; > > - unsigned long flags; > > + int ret; > > > > - spin_lock_irqsave(&host->lock, flags); > > - host->runtime_suspended = true; > > - spin_unlock_irqrestore(&host->lock, flags); > > + ret = sdhci_runtime_suspend_host(host); > > If you get an error at this point, you shouldn't continue but instead > just return an error. Maybe even return -EBUSY. Thanks for reviewing. What about just return "ret" if get an error here? Even if sdhci_runtime_suspend_host() return any error in the future, we are still safe. I'm cooking a patch to behave like this. > > Now, since sdhci_runtime_suspend_host() always returns 0 (should it be > converted to void? ), perhaps you could ignore the error completely > and return 0, as before? Thanks, Jisheng -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
