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mmc: sdhci-pxav3: fix race between runtime pm and irq

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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@marvell.com>
Cc: <stable@vger.kernel.org> # v3.9+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Jisheng Zhang 2015-01-23 18:08:21 +08:00 committed by Ulf Hansson
parent 7a30f2affa
commit 3bb10f6093
1 changed files with 5 additions and 10 deletions
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15
drivers/mmc/host/sdhci-pxav3.c
View file

@ -458,11 +458,11 @@ 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 (ret)
return ret;
clk_disable_unprepare(pxa->clk_io);
if (!IS_ERR(pxa->clk_core))
@ -476,17 +476,12 @@ static int sdhci_pxav3_runtime_resume(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;
clk_prepare_enable(pxa->clk_io);
if (!IS_ERR(pxa->clk_core))
clk_prepare_enable(pxa->clk_core);
spin_lock_irqsave(&host->lock, flags);
host->runtime_suspended = false;
spin_unlock_irqrestore(&host->lock, flags);
return 0;
return sdhci_runtime_resume_host(host);
}
#endif