Re: [PATCH] mmc: renesas_sdhi: don't overwrite TAP settings when HS400 tuning is complete

From: Ulf Hansson <ulf.hansson@linaro.org>
To: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: linux-mmc@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Subject: Re: [PATCH] mmc: renesas_sdhi: don't overwrite TAP settings when HS400 tuning is complete
Date: Thu, 7 Apr 2022 12:49:52 +0200	[thread overview]
Message-ID: <CAPDyKFoL1ew7wNXu_XjCMxQ4kTR05fdHqvwKVtfnDSFrpL4qOA@mail.gmail.com> (raw)
In-Reply-To: <20220404114902.12175-1-wsa+renesas@sang-engineering.com>

On Mon, 4 Apr 2022 at 13:49, Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
>
> When HS400 tuning is complete and HS400 is going to be activated, we
> have to keep the current number of TAPs and should not overwrite them
> with a hardcoded value. This was probably a copy&paste mistake when
> upporting HS400 support from the BSP.
>
> Fixes: 26eb2607fa28 ("mmc: renesas_sdhi: add eMMC HS400 mode support")
> Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Applied for fixes, thanks!

Kind regards
Uffe

> ---
>
> Lightly tested with a Renesas R-Car M3N SoC. I think I can't really test
> it because my TAPs are usually stable in my environment. The fix should
> be obvious, though. Shimoda-san, are you happy with it?
>
>  drivers/mmc/host/renesas_sdhi_core.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
> index 89d21231ec5f..4404ca1f98d8 100644
> --- a/drivers/mmc/host/renesas_sdhi_core.c
> +++ b/drivers/mmc/host/renesas_sdhi_core.c
> @@ -394,10 +394,10 @@ static void renesas_sdhi_hs400_complete(struct mmc_host *mmc)
>                         SH_MOBILE_SDHI_SCC_TMPPORT2_HS400OSEL) |
>                         sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_TMPPORT2));
>
> -       /* Set the sampling clock selection range of HS400 mode */
>         sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_DTCNTL,
>                        SH_MOBILE_SDHI_SCC_DTCNTL_TAPEN |
> -                      0x4 << SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_SHIFT);
> +                      sd_scc_read32(host, priv,
> +                                    SH_MOBILE_SDHI_SCC_DTCNTL));
>
>         /* Avoid bad TAP */
>         if (bad_taps & BIT(priv->tap_set)) {
> --
> 2.30.2
>