mmc: sdhci-sprd: Disable CLK_AUTO when the clock is less than 400K

When the clock is less than 400K, some SD cards fail to initialize
because CLK_AUTO is enabled.

Fixes: fb8bd90f83c4 ("mmc: sdhci-sprd: Add Spreadtrum's initial host controller")
Signed-off-by: Wenchao Chen <wenchao.chen@unisoc.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221207051909.32126-1-wenchao.chen@unisoc.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c
index bec3f9e..525f979 100644 (file)
--- a/drivers/mmc/host/sdhci-sprd.c
+++ b/drivers/mmc/host/sdhci-sprd.c
@@ -228,13 +228,15 @@ static inline void _sdhci_sprd_set_clock(struct sdhci_host *host,
        div = ((div & 0x300) >> 2) | ((div & 0xFF) << 8);
        sdhci_enable_clk(host, div);
 
-       /* enable auto gate sdhc_enable_auto_gate */
-       val = sdhci_readl(host, SDHCI_SPRD_REG_32_BUSY_POSI);
-       mask = SDHCI_SPRD_BIT_OUTR_CLK_AUTO_EN |
-              SDHCI_SPRD_BIT_INNR_CLK_AUTO_EN;
-       if (mask != (val & mask)) {
-               val |= mask;
-               sdhci_writel(host, val, SDHCI_SPRD_REG_32_BUSY_POSI);
+       /* Enable CLK_AUTO when the clock is greater than 400K. */
+       if (clk > 400000) {
+               val = sdhci_readl(host, SDHCI_SPRD_REG_32_BUSY_POSI);
+               mask = SDHCI_SPRD_BIT_OUTR_CLK_AUTO_EN |
+                       SDHCI_SPRD_BIT_INNR_CLK_AUTO_EN;
+               if (mask != (val & mask)) {
+                       val |= mask;
+                       sdhci_writel(host, val, SDHCI_SPRD_REG_32_BUSY_POSI);
+               }
        }
 }