mmc: sdhci: Disable re-tuning for HS400

[linux-beck.git] / drivers / mmc / host / sdhci.c

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 5c28c19622e6e7da2cb49eb5de16434953fa23a0..398e9e49673686e97e8f1a9116cf6bbe6507361d 100644 (file)
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1878,6 +1878,18 @@ static int sdhci_card_busy(struct mmc_host *mmc)
        return !(present_state & SDHCI_DATA_LVL_MASK);
 }
 
+static int sdhci_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+       struct sdhci_host *host = mmc_priv(mmc);
+       unsigned long flags;
+
+       spin_lock_irqsave(&host->lock, flags);
+       host->flags |= SDHCI_HS400_TUNING;
+       spin_unlock_irqrestore(&host->lock, flags);
+
+       return 0;
+}
+
 static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 {
        struct sdhci_host *host = mmc_priv(mmc);
@@ -1886,10 +1898,14 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
        int err = 0;
        unsigned long flags;
        unsigned int tuning_count = 0;
+       bool hs400_tuning;
 
        sdhci_runtime_pm_get(host);
        spin_lock_irqsave(&host->lock, flags);
 
+       hs400_tuning = host->flags & SDHCI_HS400_TUNING;
+       host->flags &= ~SDHCI_HS400_TUNING;
+
        if (host->tuning_mode == SDHCI_TUNING_MODE_1)
                tuning_count = host->tuning_count;
 
@@ -1901,8 +1917,20 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
         * tuning function has to be executed.
         */
        switch (host->timing) {
+       /* HS400 tuning is done in HS200 mode */
        case MMC_TIMING_MMC_HS400:
+               err = -EINVAL;
+               goto out_unlock;
+
        case MMC_TIMING_MMC_HS200:
+               /*
+                * Periodic re-tuning for HS400 is not expected to be needed, so
+                * disable it here.
+                */
+               if (hs400_tuning)
+                       tuning_count = 0;
+               break;
+
        case MMC_TIMING_UHS_SDR104:
                break;
 
@@ -2130,6 +2158,7 @@ static const struct mmc_host_ops sdhci_ops = {
        .hw_reset       = sdhci_hw_reset,
        .enable_sdio_irq = sdhci_enable_sdio_irq,
        .start_signal_voltage_switch    = sdhci_start_signal_voltage_switch,
+       .prepare_hs400_tuning           = sdhci_prepare_hs400_tuning,
        .execute_tuning                 = sdhci_execute_tuning,
        .card_event                     = sdhci_card_event,
        .card_busy      = sdhci_card_busy,