mmc: tmio_mmc_core: don't claim spurious interrupts

Sergei Shtylyov · storulf · commit 5c27ff5db149 · 2019-02-25T17:25:13.000+01:00
I have encountered an interrupt storm during the eMMC chip probing (and the chip finally didn't get detected). It turned out that U-Boot left the DMAC interrupts enabled while the Linux driver didn't use those. The SDHI driver's interrupt handler somehow assumes that, even if an SDIO interrupt didn't happen, it should return IRQ_HANDLED. I think that if none of the enabled interrupts happened and got handled, we should return IRQ_NONE -- that way the kernel IRQ code recoginizes a spurious interrupt and masks it off pretty quickly... Fixes: 7729c7a ("mmc: tmio: Provide separate interrupt handlers") Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Cc: stable@vger.kernel.org Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c
@@ -629,15 +629,15 @@ static bool __tmio_mmc_sdcard_irq(struct tmio_mmc_host *host, int ireg,
 	return false;
 }
 
-static void __tmio_mmc_sdio_irq(struct tmio_mmc_host *host)
+static bool __tmio_mmc_sdio_irq(struct tmio_mmc_host *host)
 {
 	struct mmc_host *mmc = host->mmc;
 	struct tmio_mmc_data *pdata = host->pdata;
 	unsigned int ireg, status;
 	unsigned int sdio_status;
 
 	if (!(pdata->flags & TMIO_MMC_SDIO_IRQ))
-		return;
+		return false;
 
 	status = sd_ctrl_read16(host, CTL_SDIO_STATUS);
 	ireg = status & TMIO_SDIO_MASK_ALL & ~host->sdio_irq_mask;
@@ -650,6 +650,8 @@ static void __tmio_mmc_sdio_irq(struct tmio_mmc_host *host)
 
 	if (mmc->caps & MMC_CAP_SDIO_IRQ && ireg & TMIO_SDIO_STAT_IOIRQ)
 		mmc_signal_sdio_irq(mmc);
+
+	return ireg;
 }
 
 irqreturn_t tmio_mmc_irq(int irq, void *devid)
@@ -668,9 +670,10 @@ irqreturn_t tmio_mmc_irq(int irq, void *devid)
 	if (__tmio_mmc_sdcard_irq(host, ireg, status))
 		return IRQ_HANDLED;
 
-	__tmio_mmc_sdio_irq(host);
+	if (__tmio_mmc_sdio_irq(host))
+		return IRQ_HANDLED;
 
-	return IRQ_HANDLED;
+	return IRQ_NONE;
 }
 EXPORT_SYMBOL_GPL(tmio_mmc_irq);
 
