[PATCH 3.16.y-ckt 054/183] mmc: sdhci-pxav3: fix race between runtime pm and irq
From: Luis Henriques
Date: Fri Mar 06 2015 - 05:55:51 EST
3.16.7-ckt8 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Jisheng Zhang <jszhang@xxxxxxxxxxx>
commit 3bb10f60933e84abfe2be69f60b3486f9b96348b upstream.
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>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci-pxav3.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c
index f62655bc1604..a30f42003fb8 100644
--- a/drivers/mmc/host/sdhci-pxav3.c
+++ b/drivers/mmc/host/sdhci-pxav3.c
@@ -448,11 +448,11 @@ 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);
- 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(pltfm_host->clk);
@@ -463,15 +463,10 @@ 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);
- unsigned long flags;
clk_prepare_enable(pltfm_host->clk);
- 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
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