On 22.10.2021 06:00, Jaehoon Chung wrote:
> 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@xxxxxxxxxxx>
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Works fine with all eMMC modules I have on my test systems.
> ---
> drivers/mmc/host/dw_mmc-exynos.c | 22 +++++++++++++++++++++-
> 1 file changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
> index 0c75810812a0..a475c249c430 100644
> --- a/drivers/mmc/host/dw_mmc-exynos.c
> +++ b/drivers/mmc/host/dw_mmc-exynos.c
> @@ -431,6 +431,7 @@ static inline u8 dw_mci_exynos_move_next_clksmpl(struct dw_mci *host)
> clksel = mci_readl(host, CLKSEL);
>
> sample = (clksel + 1) & 0x7;
> +
> clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
>
> if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
> @@ -464,6 +465,14 @@ static s8 dw_mci_exynos_get_best_clksmpl(u8 candiates)
> }
> }
>
> + /* Return a first candiates value, if there is some candiates */
> + for (i = 0; i < iter; i++) {
> + __c = ror8(candiates, i);
> + if ((__c & 0x1) == 0x1) {
> + loc = i;
> + goto out;
> + }
> + }
> out:
> return loc;
> }
> @@ -493,7 +502,18 @@ static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
> dw_mci_exynos_set_clksmpl(host, found);
> priv->tuned_sample = found;
> } else {
> - ret = -EIO;
> + /*
> + * 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.
> + */
> + if (candiates == 0) {
> + ret = -EIO;
> + dev_warn(&mmc->class_dev,
> + "There is no candiates value about clksmpl!\n");
> + } else {
> + priv->tuned_sample = dw_mci_exynos_get_clksmpl(host);
> + }
> }
>
> return ret;
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
