RE: [PATCH RFT] mmc: renesas_sdhi: limit block count to 16 bit for old revisions

[Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>]

Hi Wolfram-san,

> From: Wolfram Sang, Sent: Tuesday, March 19, 2019 7:13 PM
> 
> R-Car Gen2 has two different SDHI incarnations in the same chip. The
> older one does not support the recently introduced 32 bit register
> access to the block count register. Make sure we use this feature only
> after the first known version.
> 
> Thanks to the Renesas Testing team for this bug report!
> 
> Fixes:5603731a15ef ("mmc: tmio: fix access width of Block Count Register")
> Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---

Thank you for the patch.
Since our test team tested this patch on R-Car H2 / Lager board and the issue disappeared.
So,

Tested-by: Phong Hoang <phong.hoang.wz@renesas.com>

Best regards,
Yoshihiro Shimoda

> I could reproduce the issue on my Renesas Lager board (R-Car H2) and this patch
> fixes the issue for me. Still, if we could confirmation from the testing team,
> this would be awesome to have before applying, I think.
> 
>  drivers/mmc/host/renesas_sdhi_core.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
> index 71e13844df6c..8742e27e4e8b 100644
> --- a/drivers/mmc/host/renesas_sdhi_core.c
> +++ b/drivers/mmc/host/renesas_sdhi_core.c
> @@ -641,6 +641,7 @@ int renesas_sdhi_probe(struct platform_device *pdev,
>  	struct renesas_sdhi *priv;
>  	struct resource *res;
>  	int irq, ret, i;
> +	u16 ver;
> 
>  	of_data = of_device_get_match_data(&pdev->dev);
> 
> @@ -773,12 +774,17 @@ int renesas_sdhi_probe(struct platform_device *pdev,
>  	if (ret)
>  		goto efree;
> 
> +	ver = sd_ctrl_read16(host, CTL_VERSION);
> +	/* GEN2_SDR104 is first known SDHI to use 32bit block count */
> +	if (ver < SDHI_VER_GEN2_SDR104 && mmc_data->max_blk_count > U16_MAX)
> +		mmc_data->max_blk_count = U16_MAX;
> +
>  	ret = tmio_mmc_host_probe(host);
>  	if (ret < 0)
>  		goto edisclk;
> 
>  	/* One Gen2 SDHI incarnation does NOT have a CBSY bit */
> -	if (sd_ctrl_read16(host, CTL_VERSION) == SDHI_VER_GEN2_SDR50)
> +	if (ver == SDHI_VER_GEN2_SDR50)
>  		mmc_data->flags &= ~TMIO_MMC_HAVE_CBSY;
> 
>  	/* Enable tuning iff we have an SCC and a supported mode */
> --
> 2.11.0