1 files changed, 38 insertions, 3 deletions

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index cf8511b80782..af40d227bece 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -627,6 +627,7 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
 {
         struct dw_mci *host = slot->host;
         u32 div;
+        u32 clk_en_a;
 
         if (slot->clock != host->current_speed) {
                 div = host->bus_hz / slot->clock;
@@ -659,9 +660,11 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
                 mci_send_cmd(slot,
                              SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
 
-                /* enable clock */
-                mci_writel(host, CLKENA, ((SDMMC_CLKEN_ENABLE |
-                           SDMMC_CLKEN_LOW_PWR) << slot->id));
+                /* enable clock; only low power if no SDIO */
+                clk_en_a = SDMMC_CLKEN_ENABLE << slot->id;
+                if (!(mci_readl(host, INTMASK) & SDMMC_INT_SDIO(slot->id)))
+                        clk_en_a |= SDMMC_CLKEN_LOW_PWR << slot->id;
+                mci_writel(host, CLKENA, clk_en_a);
 
                 /* inform CIU */
                 mci_send_cmd(slot,
@@ -862,6 +865,30 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
         return present;
 }
 
+/*
+ * Disable lower power mode.
+ *
+ * Low power mode will stop the card clock when idle.  According to the
+ * description of the CLKENA register we should disable low power mode
+ * for SDIO cards if we need SDIO interrupts to work.
+ *
+ * This function is fast if low power mode is already disabled.
+ */
+static void dw_mci_disable_low_power(struct dw_mci_slot *slot)
+{
+        struct dw_mci *host = slot->host;
+        u32 clk_en_a;
+        const u32 clken_low_pwr = SDMMC_CLKEN_LOW_PWR << slot->id;
+
+        clk_en_a = mci_readl(host, CLKENA);
+
+        if (clk_en_a & clken_low_pwr) {
+                mci_writel(host, CLKENA, clk_en_a & ~clken_low_pwr);
+                mci_send_cmd(slot, SDMMC_CMD_UPD_CLK |
+                             SDMMC_CMD_PRV_DAT_WAIT, 0);
+        }
+}
+
 static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
 {
         struct dw_mci_slot *slot = mmc_priv(mmc);
@@ -871,6 +898,14 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
         /* Enable/disable Slot Specific SDIO interrupt */
         int_mask = mci_readl(host, INTMASK);
         if (enb) {
+                /*
+                 * Turn off low power mode if it was enabled.  This is a bit of
+                 * a heavy operation and we disable / enable IRQs a lot, so
+                 * we'll leave low power mode disabled and it will get
+                 * re-enabled again in dw_mci_setup_bus().
+                 */
+                dw_mci_disable_low_power(slot);
+
                 mci_writel(host, INTMASK,
                            (int_mask | SDMMC_INT_SDIO(slot->id)));
         } else {