mmc: sdhci: check interrupt flags in ISR again

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>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 80cc784..8262cad 100644 (file)
--- 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.
         */