With the interrupt support introduced in commit 066ecde sometimes the
Marvell-8987 wifi chip got stuck using the marvell-sd-uapsta-8987
vendor driver. The cause seems to be that after sending ack to all interrupts
the IRQ_SDIO still happens, but it is ignored.
To work around this, recheck the IRQ_SDIO after meson_mmc_request_done().
Inspired by 9e2582e ("mmc: mediatek: fix SDIO irq issue") which used a
similar fix to handle lost interrupts.
Fixes: 066ecde ("mmc: meson-gx: add SDIO interrupt support")
Signed-off-by: Peter Suti <peter.suti@xxxxxxxxxxxxxxxxxxx>
---
Changes in v2:
- use spin_lock instead of spin_lock_irqsave
- only reenable interrupts if they were enabled already
Changes in v3:
- Rework the patch based on feedback from Heiner Kallweit.
The IRQ does not happen on 2 CPUs and the hard IRQ is not re-entrant.
But still one SDIO IRQ is lost without this change.
After the ack, reading the SD_EMMC_STATUS BIT(15) is set, but
meson_mmc_irq() is never called again.
The fix is similar to Mediatek msdc_recheck_sdio_irq().
That platform also loses an IRQ in some cases it seems.
drivers/mmc/host/meson-gx-mmc.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 6e5ea0213b47..7d3ee2f9a7f6 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -1023,6 +1023,22 @@ static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
if (ret == IRQ_HANDLED)
meson_mmc_request_done(host->mmc, cmd->mrq);
+ /*
+ * Sometimes after we ack all raised interrupts,
+ * an IRQ_SDIO can still be pending, which can get lost.
+ *
+ * To prevent this, recheck the IRQ_SDIO here and schedule
+ * it to be processed.
+ */
+ raw_status = readl(host->regs + SD_EMMC_STATUS);
+ status = raw_status & (IRQ_EN_MASK | IRQ_SDIO);
+ if (status & IRQ_SDIO) {
+ spin_lock(&host->lock);
+ __meson_mmc_enable_sdio_irq(host->mmc, 0);
+ sdio_signal_irq(host->mmc);
+ spin_unlock(&host->lock);
+ }
+
return ret;
}
--
2.25.1
