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 a
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...
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
---
The patch is against Ulf Hansson's 'mmc.git' repo's 'fixes' branch.
drivers/mmc/host/tmio_mmc_core.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
Index: mmc/drivers/mmc/host/tmio_mmc_core.c
===================================================================
--- mmc.orig/drivers/mmc/host/tmio_mmc_core.c
+++ mmc/drivers/mmc/host/tmio_mmc_core.c
@@ -691,7 +691,7 @@ static bool __tmio_mmc_sdcard_irq(struct
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;
@@ -699,7 +699,7 @@ static void __tmio_mmc_sdio_irq(struct t
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;
@@ -712,6 +712,8 @@ static void __tmio_mmc_sdio_irq(struct t
if (mmc->caps & MMC_CAP_SDIO_IRQ && ireg & TMIO_SDIO_STAT_IOIRQ)
mmc_signal_sdio_irq(mmc);
+
+ return ireg ? true : false;
}
irqreturn_t tmio_mmc_irq(int irq, void *devid)
@@ -730,9 +732,10 @@ irqreturn_t tmio_mmc_irq(int irq, void *
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);
