> On 22 Oct 2021, at 12:21 pm, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> 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>
Tested-by: Christian Hewitt <christianshewitt@xxxxxxxxx>
v2 patch working fine with the module that triggered the original report:
[ 2.902144] mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 400000Hz, actual 396825HZ div = 63)
[ 2.912118] mmc_host mmc1: Bus speed (slot 0) = 50000000Hz (slot req 400000Hz, actual 396825HZ div = 63)
[ 3.142474] mmc_host mmc0: Bus speed (slot 0) = 200000000Hz (slot req 200000000Hz, actual 200000000HZ div = 0)
[ 3.239339] mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 52000000Hz, actual 50000000HZ div = 0)
[ 3.241388] mmc_host mmc0: Bus speed (slot 0) = 266666666Hz (slot req 200000000Hz, actual 133333333HZ div = 1)
[ 3.243310] mmc0: new HS400 MMC card at address 0001
[ 3.259191] mmcblk0: mmc0:0001 8GME4R 7.28 GiB
[ 3.302621] mmcblk0: p1 p2
[ 3.311541] mmcblk0boot0: mmc0:0001 8GME4R 4.00 MiB
[ 3.327737] mmcblk0boot1: mmc0:0001 8GME4R 4.00 MiB
[ 3.340919] mmcblk0rpmb: mmc0:0001 8GME4R 512 KiB, chardev (246:0)
Thanks!
> ---
> Changelog V2:
> - Add Marek's Tested-by tag
> - Remove unnecessary code
>
> drivers/mmc/host/dw_mmc-exynos.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
> index 0c75810812a0..1f8a3c0ddfe1 100644
> --- 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(u8 candiates)
> }
> }
>
> + /*
> + * 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(struct dw_mci_slot *slot, u32 opcode)
> priv->tuned_sample = found;
> } else {
> ret = -EIO;
> + dev_warn(&mmc->class_dev,
> + "There is no candiates value about clksmpl!\n");
> }
>
> return ret;
> --
> 2.29.0
>
