[PATCH] mmc: sdhci: fix possible scheduling while atomic

From: Andrew Bresticker
Date: Fri Jan 17 2014 - 15:04:26 EST


sdhci_execute_tuning() takes host->lock without disabling interrupts.
Use spin_lock_irq{save,restore} instead so that we avoid taking an
interrupt and scheduling while holding host->lock.

Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
---
drivers/mmc/host/sdhci.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index ec3eb30..84c80e7 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1857,12 +1857,13 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
unsigned long timeout;
int err = 0;
bool requires_tuning_nonuhs = false;
+ unsigned long flags;

host = mmc_priv(mmc);

sdhci_runtime_pm_get(host);
disable_irq(host->irq);
- spin_lock(&host->lock);
+ spin_lock_irqsave(&host->lock, flags);

ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);

@@ -1882,14 +1883,14 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
requires_tuning_nonuhs)
ctrl |= SDHCI_CTRL_EXEC_TUNING;
else {
- spin_unlock(&host->lock);
+ spin_unlock_irqrestore(&host->lock, flags);
enable_irq(host->irq);
sdhci_runtime_pm_put(host);
return 0;
}

if (host->ops->platform_execute_tuning) {
- spin_unlock(&host->lock);
+ spin_unlock_irqrestore(&host->lock, flags);
enable_irq(host->irq);
err = host->ops->platform_execute_tuning(host, opcode);
sdhci_runtime_pm_put(host);
@@ -1963,7 +1964,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
host->cmd = NULL;
host->mrq = NULL;

- spin_unlock(&host->lock);
+ spin_unlock_irqrestore(&host->lock, flags);
enable_irq(host->irq);

/* Wait for Buffer Read Ready interrupt */
@@ -1971,7 +1972,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
(host->tuning_done == 1),
msecs_to_jiffies(50));
disable_irq(host->irq);
- spin_lock(&host->lock);
+ spin_lock_irqsave(&host->lock, flags);

if (!host->tuning_done) {
pr_info(DRIVER_NAME ": Timeout waiting for "
@@ -2046,7 +2047,7 @@ out:
err = 0;

sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
- spin_unlock(&host->lock);
+ spin_unlock_irqrestore(&host->lock, flags);
enable_irq(host->irq);
sdhci_runtime_pm_put(host);

--
1.8.5.2

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