Re: [PATCH v5 1/5] mmc: core: Extend mmc_of_parse() to parse CQE bindings

[Veerabhadrarao Badiganti]

On 4/28/2020 5:26 AM, Chun-Hung Wu wrote:
> Parse CQE bindings "supports-cqe" and "disable-cqe-dcmd"
> in mmc_of_parse().
>
> Signed-off-by: Chun-Hung Wu <chun-hung.wu@xxxxxxxxxxxx>
> ---
>   drivers/mmc/core/host.c | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
> index c876872..47521c6 100644
> --- a/drivers/mmc/core/host.c
> +++ b/drivers/mmc/core/host.c
> @@ -302,6 +302,11 @@ int mmc_of_parse(struct mmc_host *host)
>   		host->caps2 |= MMC_CAP2_NO_SD;
>   	if (device_property_read_bool(dev, "no-mmc"))
>   		host->caps2 |= MMC_CAP2_NO_MMC;
> +	if (device_property_read_bool(dev, "supports-cqe"))
> +		host->caps2 |= MMC_CAP2_CQE;

This change is breaking emmc driver on qcom platforms where this dt 
property is defined.

[ÂÂÂ 1.543453]Â cqhci_deactivate+0xc/0x38
[ÂÂÂ 1.545627]Â sdhci_msm_reset+0x40/0x58
[ÂÂÂ 1.549447]Â sdhci_do_reset+0x48/0x7c
[ÂÂÂ 1.553180]Â __sdhci_read_caps+0x7c/0x214
[ÂÂÂ 1.556913]Â sdhci_setup_host+0x58/0xce8
[ÂÂÂ 1.560905]Â sdhci_msm_probe+0x588/0x8a4
[ÂÂÂ 1.564900]Â platform_drv_probe+0x4c/0xb0

So, we cant have this flag defined before sdhci_setup_host().

I will have to clear this cap and re-enable it in our initialization.

> +	if (!device_property_read_bool(dev, "disable-cqe-dcmd")) {
> +		host->caps2 |= MMC_CAP2_CQE_DCMD;
> +	}
>   
>   	/* Must be after "non-removable" check */
>   	if (device_property_read_u32(dev, "fixed-emmc-driver-type", &drv_type) == 0) {