| Message ID | 1399591234-13089-5-git-send-email-afenkart@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Friday 09 May 2014 04:50 AM, Andreas Fenkart wrote: > On multicores, an sdio irq handler could be running in parallel to > runtime suspend. In the worst case it could be waiting for the spinlock > held by the runtime suspend. When runtime suspend is complete and the > functional clock (fclk) turned off, the irq handler will continue and > cause a SIGBUS on the first register access. > > Signed-off-by: Andreas Fenkart <afenkart@gmail.com> > Acked-by: Balaji T K <balajitk@ti.com> > diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c > index 14857d7..47a5982 100644 > --- a/drivers/mmc/host/omap_hsmmc.c > +++ b/drivers/mmc/host/omap_hsmmc.c > @@ -134,6 +134,9 @@ static void apply_clk_hack(struct device *dev) > #define SRD (1 << 26) > #define SOFTRESET (1 << 1) > > +/* PSTATE */ > +#define DLEV_DAT(x) (1 << (20 + (x))) > + > /* Interrupt masks for IE and ISE register */ > #define CC_EN (1 << 0) > #define TC_EN (1 << 1) > @@ -2455,6 +2458,7 @@ static int omap_hsmmc_runtime_suspend(struct device *dev) > { > struct omap_hsmmc_host *host; > unsigned long flags; > + int ret = 0; > > host = platform_get_drvdata(to_platform_device(dev)); > omap_hsmmc_context_save(host); > @@ -2466,14 +2470,29 @@ static int omap_hsmmc_runtime_suspend(struct device *dev) > /* disable sdio irq handling to prevent race */ > OMAP_HSMMC_WRITE(host->base, ISE, 0); > OMAP_HSMMC_WRITE(host->base, IE, 0); > - OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR); > + > + if (!(OMAP_HSMMC_READ(host->base, PSTATE) & DLEV_DAT(1))) { > + /* > + * dat1 line low, pending sdio irq > + * race condition: possible irq handler running on > + * multi-core, abort > + */ > + dev_dbg(dev, "pending sdio irq, abort suspend\n"); > + OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR); > + OMAP_HSMMC_WRITE(host->base, ISE, CIRQ_EN); > + OMAP_HSMMC_WRITE(host->base, IE, CIRQ_EN); > + pm_runtime_mark_last_busy(dev); > + ret = -EBUSY; > + goto abort; > + } > > WARN_ON(host->flags & HSMMC_WAKE_IRQ_ENABLED); > enable_irq(host->wake_irq); > host->flags |= HSMMC_WAKE_IRQ_ENABLED; > } > +abort: > spin_unlock_irqrestore(&host->irq_lock, flags); > - return 0; > + return ret; > } > > static int omap_hsmmc_runtime_resume(struct device *dev) > -- 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
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index 14857d7..47a5982 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -134,6 +134,9 @@ static void apply_clk_hack(struct device *dev) #define SRD (1 << 26) #define SOFTRESET (1 << 1) +/* PSTATE */ +#define DLEV_DAT(x) (1 << (20 + (x))) + /* Interrupt masks for IE and ISE register */ #define CC_EN (1 << 0) #define TC_EN (1 << 1) @@ -2455,6 +2458,7 @@ static int omap_hsmmc_runtime_suspend(struct device *dev) { struct omap_hsmmc_host *host; unsigned long flags; + int ret = 0; host = platform_get_drvdata(to_platform_device(dev)); omap_hsmmc_context_save(host); @@ -2466,14 +2470,29 @@ static int omap_hsmmc_runtime_suspend(struct device *dev) /* disable sdio irq handling to prevent race */ OMAP_HSMMC_WRITE(host->base, ISE, 0); OMAP_HSMMC_WRITE(host->base, IE, 0); - OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR); + + if (!(OMAP_HSMMC_READ(host->base, PSTATE) & DLEV_DAT(1))) { + /* + * dat1 line low, pending sdio irq + * race condition: possible irq handler running on + * multi-core, abort + */ + dev_dbg(dev, "pending sdio irq, abort suspend\n"); + OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR); + OMAP_HSMMC_WRITE(host->base, ISE, CIRQ_EN); + OMAP_HSMMC_WRITE(host->base, IE, CIRQ_EN); + pm_runtime_mark_last_busy(dev); + ret = -EBUSY; + goto abort; + } WARN_ON(host->flags & HSMMC_WAKE_IRQ_ENABLED); enable_irq(host->wake_irq); host->flags |= HSMMC_WAKE_IRQ_ENABLED; } +abort: spin_unlock_irqrestore(&host->irq_lock, flags); - return 0; + return ret; } static int omap_hsmmc_runtime_resume(struct device *dev)
On multicores, an sdio irq handler could be running in parallel to runtime suspend. In the worst case it could be waiting for the spinlock held by the runtime suspend. When runtime suspend is complete and the functional clock (fclk) turned off, the irq handler will continue and cause a SIGBUS on the first register access. Signed-off-by: Andreas Fenkart <afenkart@gmail.com>