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Subject: Re: [PATCH] mmc: renesas_sdhi: Set the SDBUF after reset
To: Claudiu <claudiu.beznea@tuxon.dev>, <wsa+renesas@sang-engineering.com>,
	<ulf.hansson@linaro.org>
CC: <linux-mmc@vger.kernel.org>, <linux-renesas-soc@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, Claudiu Beznea
	<claudiu.beznea.uj@bp.renesas.com>, Hien Huynh <hien.huynh.px@renesas.com>
References: <20240313093031.3507979-1-claudiu.beznea.uj@bp.renesas.com>
From: Sergey Shtylyov <s.shtylyov@omp.ru>
Organization: Open Mobile Platform
Message-ID: <53b9d9f7-921d-3a0a-5a1c-e18e6fd1dcf6@omp.ru>
Date: Wed, 13 Mar 2024 15:23:54 +0300
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On 3/13/24 12:30 PM, Claudiu wrote:

> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> 
> For development purpose, renesas_sdhi_probe() could be called w/
> dma_ops = NULL to force the usage of PIO mode. In this case the
> renesas_sdhi_enable_dma() will not be called before transferring data.
> 
> If renesas_sdhi_enable_dma() is not called, renesas_sdhi_clk_enable()
> call from renesas_sdhi_probe() will configure SDBUF by calling the
> renesas_sdhi_sdbuf_width() function, but then SDBUF will be reseted in

   s/reseted/reset/.

> tmio_mmc_host_probe() when calling tmio_mmc_reset() though host->reset().
> If SDBUF is zero the data transfer will not work in PIO mode for RZ/G3S.
> 
> To fix this call again the renesas_sdhi_sdbuf_width(host, 16); in

   Semicolon clearly doesn't fit here...

> renesas_sdhi_reset(). The call of renesas_sdhi_sdbuf_width() was not
> removed from renesas_sdhi_clk_enable() as the host->reset() is optional.
> 
> Co-developed-by: Hien Huynh <hien.huynh.px@renesas.com>
> Signed-off-by: Hien Huynh <hien.huynh.px@renesas.com>
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
[...]

> diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
> index c675dec587ef..b51e04fa5445 100644
> --- a/drivers/mmc/host/renesas_sdhi_core.c
> +++ b/drivers/mmc/host/renesas_sdhi_core.c
> @@ -589,6 +589,12 @@ static void renesas_sdhi_reset(struct tmio_mmc_host *host, bool preserve)
>  			sd_ctrl_write16(host, CTL_RESET_SD, 0x0001);
>  			priv->needs_adjust_hs400 = false;
>  			renesas_sdhi_set_clock(host, host->clk_cache);
> +
> +			/*
> +			 * In case the controller works in PIO mode the SDBUF needs to be set as its

   Well, it won't hurt wrapping the comment at 80 columns here...

> +			 * reset value is zero.
> +			 */
> +			renesas_sdhi_sdbuf_width(host, 16);
>  		} else if (priv->scc_ctl) {
>  			renesas_sdhi_scc_reset(host, priv);
>  		}

MBR, Sergey