mmc: dw_mmc: Re-store SDIO IRQs mask at system resume

In cases when SDIO IRQs have been enabled, runtime suspend is prevented by
the driver. However, this still means dw_mci_runtime_suspend|resume() gets
called during system suspend/resume, via pm_runtime_force_suspend|resume().
This means during system suspend/resume, the register context of the dw_mmc
device most likely loses its register context, even in cases when SDIO IRQs
have been enabled.

To re-enable the SDIO IRQs during system resume, the dw_mmc driver
currently relies on the mmc core to re-enable the SDIO IRQs when it resumes
the SDIO card, but this isn't the recommended solution. Instead, it's
better to deal with this locally in the dw_mmc driver, so let's do that.

Tested-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index eea52e2..79c55c7 100644 (file)
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -3460,6 +3460,10 @@ int dw_mci_runtime_resume(struct device *dev)
        /* Force setup bus to guarantee available clock output */
        dw_mci_setup_bus(host->slot, true);
 
+       /* Re-enable SDIO interrupts. */
+       if (sdio_irq_claimed(host->slot->mmc))
+               __dw_mci_enable_sdio_irq(host->slot, 1);
+
        /* Now that slots are all setup, we can enable card detect */
        dw_mci_enable_cd(host);