mmc: dw_mmc: Prevent runtime PM suspend when SDIO IRQs are enabled

To be able to handle SDIO IRQs the dw_mmc device needs to be powered and
providing clock to the SDIO card. Therefore, we must not allow the device
to be runtime PM suspended while SDIO IRQs are enabled.

To fix this, let's increase the runtime PM usage count while the mmc core
enables SDIO IRQs. Later when the mmc core tells dw_mmc to disable SDIO
IRQs, we drop the usage count to again allow runtime PM suspend.

This now becomes the default behaviour for dw_mmc. In cases where SDIO IRQs
can be re-routed as GPIO wake-ups during runtime PM suspend, one could
potentially allow runtime PM suspend. However, that will have to be
addressed as a separate change on top of this one.

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

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 635d76cd1ef0292a058e2b7b556a2293bf0d2dd9..454b847062b30c61257ce763d8c43043a7685c53 100644 (file)
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1664,8 +1664,15 @@ static void __dw_mci_enable_sdio_irq(struct dw_mci_slot *slot, int enb)
 static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
 {
        struct dw_mci_slot *slot = mmc_priv(mmc);
+       struct dw_mci *host = slot->host;
 
        __dw_mci_enable_sdio_irq(slot, enb);
+
+       /* Avoid runtime suspending the device when SDIO IRQ is enabled */
+       if (enb)
+               pm_runtime_get_noresume(host->dev);
+       else
+               pm_runtime_put_noidle(host->dev);
 }
 
 static void dw_mci_ack_sdio_irq(struct mmc_host *mmc)