commit 7ab650017bb7340b15bd1deca9121016736249d9
author Pali Rohár <pali@kernel.org> Fri Apr 29 20:27:34 2022 +0200
committer Jaehoon Chung <jh80.chung@samsung.com> Wed Jul 27 15:19:08 2022 +0900
tree a03dd1926c21b65d0818e4e491f24325a48afcef
parent e91457a07728dbfbd931097e8ce5b3fb9147306c

mmc: fsl_esdhc: Fix 'Internal clock never stabilised.' error

Only newer eSDHC controllers set PRSSTAT_SDSTB flag. So do not wait until
flag PRSSTAT_SDSTB is set on old pre-2.2 controllers. Instead sleep for
fixed amount of time like it was before commit 6f883e501b65 ("mmc:
fsl_esdhc: Add emmc hs200 support").

This change fixes error 'Internal clock never stabilised.' which is printed
on P2020 board at every access to SD card.

Fixes: 6f883e501b65 ("mmc: fsl_esdhc: Add emmc hs200 support")
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>

drivers/mmc/fsl_esdhc.c

diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
index b49a7b4..ca5a879 100644
--- a/drivers/mmc/fsl_esdhc.c
+++ b/drivers/mmc/fsl_esdhc.c
@@ -504,6 +504,7 @@
 	u32 time_out;
 	u32 value;
 	uint clk;
+	u32 hostver;
 
 	if (clock < mmc->cfg->f_min)
 		clock = mmc->cfg->f_min;
@@ -544,6 +545,14 @@
 
 	esdhc_clrsetbits32(&regs->sysctl, SYSCTL_CLOCK_MASK, clk);
 
+	/* Only newer eSDHC controllers set PRSSTAT_SDSTB flag */
+	hostver = esdhc_read32(&priv->esdhc_regs->hostver);
+	if (HOSTVER_VENDOR(hostver) <= VENDOR_V_22) {
+		udelay(10000);
+		esdhc_setbits32(&regs->sysctl, SYSCTL_PEREN | SYSCTL_CKEN);
+		return;
+	}
+
 	time_out = 20;
 	value = PRSSTAT_SDSTB;
 	while (!(esdhc_read32(&regs->prsstat) & value)) {
@@ -563,6 +572,7 @@
 	struct fsl_esdhc *regs = priv->esdhc_regs;
 	u32 value;
 	u32 time_out;
+	u32 hostver;
 
 	value = esdhc_read32(&regs->sysctl);
 
@@ -573,6 +583,13 @@
 
 	esdhc_write32(&regs->sysctl, value);
 
+	/* Only newer eSDHC controllers set PRSSTAT_SDSTB flag */
+	hostver = esdhc_read32(&priv->esdhc_regs->hostver);
+	if (HOSTVER_VENDOR(hostver) <= VENDOR_V_22) {
+		udelay(10000);
+		return;
+	}
+
 	time_out = 20;
 	value = PRSSTAT_SDSTB;
 	while (!(esdhc_read32(&regs->prsstat) & value)) {