2024-03-13 09:31:13

by Claudiu

[permalink] [raw]
Subject: [PATCH] mmc: renesas_sdhi: Set the SDBUF after reset

From: Claudiu Beznea <[email protected]>

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 <[email protected]>
Signed-off-by: Hien Huynh <[email protected]>
Signed-off-by: Claudiu Beznea <[email protected]>
---
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



2024-03-13 12:24:24

by Sergey Shtylyov

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

On 3/13/24 12:30 PM, Claudiu wrote:

> From: Claudiu Beznea <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Hien Huynh <[email protected]>
> Signed-off-by: Claudiu Beznea <[email protected]>
[...]

> 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