Re: [PATCH v5 3/3] mmc: sdhci-tegra: Issue CMD and DAT resets together

[Adrian Hunter <adrian.hunter@intel.com>]

On 27/09/22 14:13, Prathamesh Shete wrote:
> In case of error condition to avoid system crash
> Tegra SDMMC controller requires CMD and DAT resets
> issued together. SDHCI controller FSM goes into
> bad state due to rapid SD card hot-plug event.
> Issuing reset on the CMD FSM before DATA FSM results
> in kernel panic, hence add support to issue CMD and
> DAT resets together.
> This is applicable to Tegra186 and later chips.
> 
> Signed-off-by: Aniruddha TVS Rao <anrao@nvidia.com>
> Signed-off-by: Prathamesh Shete <pshete@nvidia.com>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>  drivers/mmc/host/sdhci-tegra.c | 3 ++-
>  drivers/mmc/host/sdhci.c       | 5 +++++
>  drivers/mmc/host/sdhci.h       | 2 ++
>  3 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index 46f37cc26dbb..61dc5ee0726d 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -1536,7 +1536,8 @@ static const struct sdhci_pltfm_data sdhci_tegra186_pdata = {
>  		  SDHCI_QUIRK_NO_HISPD_BIT |
>  		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
>  		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
> -	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
> +	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
> +		   SDHCI_QUIRK2_ISSUE_CMD_DAT_RESET_TOGETHER,
>  	.ops  = &tegra186_sdhci_ops,
>  };
>  
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 2b5dda521b0e..8512a69f1aae 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -270,6 +270,11 @@ enum sdhci_reset_reason {
>  
>  static void sdhci_reset_for_reason(struct sdhci_host *host, enum sdhci_reset_reason reason)
>  {
> +	if (host->quirks2 &
> +		SDHCI_QUIRK2_ISSUE_CMD_DAT_RESET_TOGETHER) {
> +		sdhci_do_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
> +		return;
> +	}
>  	switch (reason) {
>  	case SDHCI_RESET_FOR_INIT:
>  		sdhci_do_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index d750c464bd1e..6a5766774b05 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -478,6 +478,8 @@ struct sdhci_host {
>   * block count.
>   */
>  #define SDHCI_QUIRK2_USE_32BIT_BLK_CNT			(1<<18)
> +/* Issue CMD and DATA reset together */
> +#define SDHCI_QUIRK2_ISSUE_CMD_DAT_RESET_TOGETHER	(1<<19)
>  
>  	int irq;		/* Device IRQ */
>  	void __iomem *ioaddr;	/* Mapped address */