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 <[email protected]> --- 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);
