[PATCH] mmc: renesas_sdhi: Set the SDBUF after reset

[PATCH] mmc: renesas_sdhi: Set the SDBUF after reset

[Claudiu]

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
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
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>
---
 drivers/mmc/host/renesas_sdhi_core.c | 6 ++++++
 1 file changed, 6 insertions(+)

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
+			 * reset value is zero.
+			 */
+			renesas_sdhi_sdbuf_width(host, 16);
 		} else if (priv->scc_ctl) {
 			renesas_sdhi_scc_reset(host, priv);
 		}
-- 
2.39.2

Re: [PATCH] mmc: renesas_sdhi: Set the SDBUF after reset

[Sergey Shtylyov]

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