Re: [PATCH 1/5] mmc: sdhci-of-arasan: Fix SDHCI_RESET_ALL for CQHCI

[Guenter Roeck <linux@roeck-us.net>]

On Mon, Oct 17, 2022 at 08:57:20PM -0700, Brian Norris wrote:
> SDHCI_RESET_ALL resets will reset the hardware CQE state, but we aren't
> tracking that properly in software. When out of sync, we may trigger
> various timeouts.
> 
> It's not typical to perform resets while CQE is enabled, but one
> particular case I hit commonly enough: mmc_suspend() -> mmc_power_off().
> Typically we will eventually deactivate CQE (cqhci_suspend() ->
> cqhci_deactivate()), but that's not guaranteed -- in particular, if
> we perform a partial (e.g., interrupted) system suspend.
> 
> The same bug was already found and fixed for two other drivers, in v5.7
> and v5.9:
> 
> 5cf583f1fb9c mmc: sdhci-msm: Deactivate CQE during SDHC reset
> df57d73276b8 mmc: sdhci-pci: Fix SDHCI_RESET_ALL for CQHCI for Intel GLK-based controllers
> 
> The latter is especially prescient, saying "other drivers using CQHCI
> might benefit from a similar change, if they also have CQHCI reset by
> SDHCI_RESET_ALL."
> 
> So like these other patches, deactivate CQHCI when resetting the
> controller. Also, move around the DT/caps handling, because
> sdhci_setup_host() performs resets before we've initialized CQHCI. This
> is the pattern followed in other SDHCI/CQHCI drivers.
> 
> Fixes: 84362d79f436 ("mmc: sdhci-of-arasan: Add CQHCI support for arasan,sdhci-5.1")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Brian Norris <briannorris@chromium.org>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
> 
>  drivers/mmc/host/sdhci-of-arasan.c | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index 3997cad1f793..1988a703781a 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -366,6 +366,10 @@ static void sdhci_arasan_reset(struct sdhci_host *host, u8 mask)
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>  	struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
>  
> +	if ((host->mmc->caps2 & MMC_CAP2_CQE) && (mask & SDHCI_RESET_ALL) &&
> +	    sdhci_arasan->has_cqe)
> +		cqhci_deactivate(host->mmc);
> +
>  	sdhci_reset(host, mask);
>  
>  	if (sdhci_arasan->quirks & SDHCI_ARASAN_QUIRK_FORCE_CDTEST) {
> @@ -1521,7 +1525,8 @@ static int sdhci_arasan_register_sdclk(struct sdhci_arasan_data *sdhci_arasan,
>  	return 0;
>  }
>  
> -static int sdhci_arasan_add_host(struct sdhci_arasan_data *sdhci_arasan)
> +static int sdhci_arasan_add_host(struct sdhci_arasan_data *sdhci_arasan,
> +				 struct device_node *np)
>  {
>  	struct sdhci_host *host = sdhci_arasan->host;
>  	struct cqhci_host *cq_host;
> @@ -1549,6 +1554,10 @@ static int sdhci_arasan_add_host(struct sdhci_arasan_data *sdhci_arasan)
>  	if (dma64)
>  		cq_host->caps |= CQHCI_TASK_DESC_SZ_128;
>  
> +	host->mmc->caps2 |= MMC_CAP2_CQE;
> +	if (!of_property_read_bool(np, "disable-cqe-dcmd"))
> +		host->mmc->caps2 |= MMC_CAP2_CQE_DCMD;
> +
>  	ret = cqhci_init(cq_host, host->mmc, dma64);
>  	if (ret)
>  		goto cleanup;
> @@ -1705,13 +1714,9 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>  		host->mmc_host_ops.start_signal_voltage_switch =
>  					sdhci_arasan_voltage_switch;
>  		sdhci_arasan->has_cqe = true;
> -		host->mmc->caps2 |= MMC_CAP2_CQE;
> -
> -		if (!of_property_read_bool(np, "disable-cqe-dcmd"))
> -			host->mmc->caps2 |= MMC_CAP2_CQE_DCMD;
>  	}
>  
> -	ret = sdhci_arasan_add_host(sdhci_arasan);
> +	ret = sdhci_arasan_add_host(sdhci_arasan, np);
>  	if (ret)
>  		goto err_add_host;
>  
> -- 
> 2.38.0.413.g74048e4d9e-goog
>