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Subject[PATCH v2] mmc: sdhci: check interrupt flags in ISR again
Date
When using MSI it is possible that a new MSI is sent while an earlier
MSI is currently handled. In this case SDHCI_INT_STATUS only contains
SDHCI_INT_RESPONSE and the ISR would not be called again. But at the end
of the ISR SDHCI_INT_DATA_END is now also pending which would be ignored.

Fix this by rereading the interrupt flags in the ISR until no interrupt
we care is pending.

Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
---
Changes in v2:
* rearranged code a bit and added a maximum loop counter as suggested
by Adrian

drivers/mmc/host/sdhci.c | 19 ++++++++++++-------
1 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 8d66706..4fe4461 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2267,8 +2267,8 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
{
irqreturn_t result;
struct sdhci_host *host = dev_id;
- u32 intmask;
- int cardint = 0;
+ u32 intmask, unexpected = 0;
+ int cardint = 0, max_loops = 16;

spin_lock(&host->lock);

@@ -2286,6 +2286,7 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
goto out;
}

+again:
DBG("*** %s got interrupt: 0x%08x\n",
mmc_hostname(host->mmc), intmask);

@@ -2344,19 +2345,23 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
intmask &= ~SDHCI_INT_CARD_INT;

if (intmask) {
- pr_err("%s: Unexpected interrupt 0x%08x.\n",
- mmc_hostname(host->mmc), intmask);
- sdhci_dumpregs(host);
-
+ unexpected |= intmask;
sdhci_writel(host, intmask, SDHCI_INT_STATUS);
}

result = IRQ_HANDLED;

- mmiowb();
+ intmask = sdhci_readl(host, SDHCI_INT_STATUS);
+ if (intmask && --max_loops)
+ goto again;
out:
spin_unlock(&host->lock);

+ if (unexpected) {
+ pr_err("%s: Unexpected interrupt 0x%08x.\n",
+ mmc_hostname(host->mmc), unexpected);
+ sdhci_dumpregs(host);
+ }
/*
* We have to delay this as it calls back into the driver.
*/
--
1.7.3.4


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