[PATCH 5.10 23/77] mmc: dw_mmc: exynos: fix the finding clock sample value

Greg Kroah-Hartman
2021-11-01T09:34:50Z

From: Jaehoon Chung <jh80.chung@samsung.com>

commit 697542bceae51f7620af333b065dd09d213629fb upstream.

Even though there are candiates value if can't find best value, it's
returned -EIO. It's not proper behavior.
If there is not best value, use a first candiate value to work eMMC.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Christian Hewitt <christianshewitt@gmail.com>
Cc: stable@vger.kernel.org
Fixes: c537a1c5ff63 ("mmc: dw_mmc: exynos: add variable delay tuning sequence")
Link: https://lore.kernel.org/r/20211022082106.1557-1-jh80.chung@samsung.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/mmc/host/dw_mmc-exynos.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

--- a/drivers/mmc/host/dw_mmc-exynos.c
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -464,6 +464,18 @@ static s8 dw_mci_exynos_get_best_clksmpl
}
}

+ /*
+ * If there is no cadiates value, then it needs to return -EIO.
+ * If there are candiates values and don't find bset clk sample value,
+ * then use a first candiates clock sample value.
+ */
+ for (i = 0; i < iter; i++) {
+ __c = ror8(candiates, i);
+ if ((__c & 0x1) == 0x1) {
+ loc = i;
+ goto out;
+ }
+ }
out:
return loc;
}
@@ -494,6 +506,8 @@ static int dw_mci_exynos_execute_tuning(
priv->tuned_sample = found;
} else {
ret = -EIO;
+ dev_warn(&mmc->class_dev,
+ "There is no candiates value about clksmpl!\n");
}

return ret;