Re: [PATCH v1] mmc: sdhci-of-dwcmshc: th1520: Increase tuning loop count to 128

From: Adrian Hunter
Date: Thu Apr 04 2024 - 04:28:24 EST


On 2/04/24 12:35, Maksim Kiselev wrote:
> Fix SD card tuning error by increasing tuning loop count
> from 40(MAX_TUNING_LOOP) to 128.
>
> For some reason the tuning algorithm requires to move through all the taps
> of delay line even if the THRESHOLD_MODE (bit 2 in AT_CTRL_R) is used
> instead of the LARGEST_WIN_MODE.
>
> Tested-by: Drew Fustini <drew@xxxxxxxx>
> Tested-by: Xi Ruoyao <xry111@xxxxxxxxxxx>
> Signed-off-by: Maksim Kiselev <bigunclemax@xxxxxxxxx>

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

> ---
> Previous discussion was here:
> https://lore.kernel.org/lkml/CALHCpMhc1F5Ue7U_gsDXREHUZRVQJNYRCJxYxoNqbN=-39jf7A@xxxxxxxxxxxxxx/
>
> drivers/mmc/host/sdhci-of-dwcmshc.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> index 8d6cfb648096..1001b6ea1a89 100644
> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> @@ -706,6 +706,7 @@ static int th1520_execute_tuning(struct sdhci_host *host, u32 opcode)
>
> /* perform tuning */
> sdhci_start_tuning(host);
> + host->tuning_loop_count = 128;
> host->tuning_err = __sdhci_execute_tuning(host, opcode);
> if (host->tuning_err) {
> /* disable auto-tuning upon tuning error */