On Wed, 10 Apr 2024 at 15:54, Claudiu Beznea <claudiu.beznea@xxxxxxxxx> wrote:
>
> 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 reset 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@xxxxxxxxxxx>
> Signed-off-by: Hien Huynh <hien.huynh.px@xxxxxxxxxxx>
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
Wolfram, when you have the time, can we get your opinion on this one?
Kind regards
Uffe
> ---
>
> Changes in v2:
> - fixed typos in commit description
> - limit the comment lines to 80 chars
>
> 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 f84f60139bcf..5233731a94c4 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
>
