Re: [PATCH V2 2/4] mmc: sdhci: Avoid unnecessary re-configuration

[Robert Marko <robimarko@gmail.com>]

On 28. 11. 2022. 14:32, Adrian Hunter wrote:
> Avoid re-configuring UHS and preset settings when the settings have not
> changed, irrespective of whether the clock is turning on.
>
> Tested-by: Haibo Chen <haibo.chen@nxp.com>
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>

Hi, this is breaking sdhci-msm on IPQ8074 in next-20221130 for me
and reverting it makes the eMMC work again.

I get a lot of:

[    2.727287] mmc0: tuning execution failed: -5
[    2.727323] mmc0: error -5 whilst initialising MMC card
[    3.846540] mmc0: tuning execution failed: -5
[    3.846564] mmc0: error -5 whilst initialising MMC card
[    4.966517] mmc0: tuning execution failed: -5
[    4.966539] mmc0: error -5 whilst initialising MMC card
[    6.096486] mmc0: tuning execution failed: -5
[    6.096508] mmc0: error -5 whilst initialising MMC card
[    7.206431] mmc0: tuning execution failed: -5
[    7.206454] mmc0: error -5 whilst initialising MMC card

Regards,
Robert

> ---
>   drivers/mmc/host/sdhci.c | 8 ++------
>   1 file changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 64750fbb0ac8..17e5ccf9a855 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2315,7 +2315,6 @@ void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>   {
>   	struct sdhci_host *host = mmc_priv(mmc);
>   	bool reinit_uhs = host->reinit_uhs;
> -	bool turning_on_clk = false;
>   	u8 ctrl;
>   
>   	host->reinit_uhs = false;
> @@ -2345,8 +2344,6 @@ void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>   		sdhci_enable_preset_value(host, false);
>   
>   	if (!ios->clock || ios->clock != host->clock) {
> -		turning_on_clk = ios->clock && !host->clock;
> -
>   		host->ops->set_clock(host, ios->clock);
>   		host->clock = ios->clock;
>   
> @@ -2374,11 +2371,10 @@ void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>   	host->ops->set_bus_width(host, ios->bus_width);
>   
>   	/*
> -	 * Special case to avoid multiple clock changes during voltage
> -	 * switching.
> +	 * Avoid unnecessary changes. In particular, this avoids multiple clock
> +	 * changes during voltage switching.
>   	 */
>   	if (!reinit_uhs &&
> -	    turning_on_clk &&
>   	    host->timing == ios->timing &&
>   	    host->version >= SDHCI_SPEC_300 &&
>   	    !sdhci_presetable_values_change(host, ios))