mmc: sdhci-esdhc-imx: correct the tuning start tap and step setting

commit 1e336aa upstream.

Current code logic may be impacted by the setting of ROM/Bootloader,
so unmask these bits first, then setting these bits accordingly.

Fixes: 2b16cf3 ("mmc: sdhci-esdhc-imx: move tuning static configuration into hwinit function")
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221207112315.1812222-1-haibo.chen@nxp.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/mmc/host/sdhci-esdhc-imx.c

@@ -107,6 +107,7 @@
 #define ESDHC_TUNING_START_TAP_DEFAULT	0x1
 #define ESDHC_TUNING_START_TAP_MASK	0x7f
 #define ESDHC_TUNING_CMD_CRC_CHECK_DISABLE	(1 << 7)
+#define ESDHC_TUNING_STEP_DEFAULT	0x1
 #define ESDHC_TUNING_STEP_MASK		0x00070000
 #define ESDHC_TUNING_STEP_SHIFT		16
 
@@ -1361,7 +1362,7 @@ static void sdhci_esdhc_imx_hwinit(struct sdhci_host *host)
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
 	struct cqhci_host *cq_host = host->mmc->cqe_private;
-	int tmp;
+	u32 tmp;
 
 	if (esdhc_is_usdhc(imx_data)) {
 		/*
@@ -1416,17 +1417,24 @@ static void sdhci_esdhc_imx_hwinit(struct sdhci_host *host)
 
 		if (imx_data->socdata->flags & ESDHC_FLAG_STD_TUNING) {
 			tmp = readl(host->ioaddr + ESDHC_TUNING_CTRL);
-			tmp |= ESDHC_STD_TUNING_EN |
-				ESDHC_TUNING_START_TAP_DEFAULT;
-			if (imx_data->boarddata.tuning_start_tap) {
-				tmp &= ~ESDHC_TUNING_START_TAP_MASK;
+			tmp |= ESDHC_STD_TUNING_EN;
+
+			/*
+			 * ROM code or bootloader may config the start tap
+			 * and step, unmask them first.
+			 */
+			tmp &= ~(ESDHC_TUNING_START_TAP_MASK | ESDHC_TUNING_STEP_MASK);
+			if (imx_data->boarddata.tuning_start_tap)
 				tmp |= imx_data->boarddata.tuning_start_tap;
-			}
+			else
+				tmp |= ESDHC_TUNING_START_TAP_DEFAULT;
 
 			if (imx_data->boarddata.tuning_step) {
-				tmp &= ~ESDHC_TUNING_STEP_MASK;
 				tmp |= imx_data->boarddata.tuning_step
 					<< ESDHC_TUNING_STEP_SHIFT;
+			} else {
+				tmp |= ESDHC_TUNING_STEP_DEFAULT
+					<< ESDHC_TUNING_STEP_SHIFT;
 			}
 
 			/* Disable the CMD CRC check for tuning, if not, need to