Re: [PATCH] Revert "mmc: sdhci: Disable SD card clock before changing parameters"

[Adrian Hunter]

On 24/06/2025 14:09, Ulf Hansson wrote:
> It has turned out the trying to strictly conform to the SDHCI specification
> is causing problems. Let's revert and start over.
> 
> This reverts commit fb3bbc46c94f261b6156ee863c1b06c84cf157dc.
> 
> Cc: Erick Shepherd <erick.shepherd@xxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: fb3bbc46c94f ("mmc: sdhci: Disable SD card clock before changing parameters")
> Suggested-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Reported-by: Jonathan Liu <net147@xxxxxxxxx>
> Reported-by: Salvatore Bonaccorso <carnil@xxxxxxxxxx>
> Closes: https://bugs.debian.org/1108065
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>

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

> ---
>  drivers/mmc/host/sdhci.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 4c6c2cc93c41..3a17821efa5c 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2065,15 +2065,10 @@ void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
>  
>  	host->mmc->actual_clock = 0;
>  
> -	clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> -	if (clk & SDHCI_CLOCK_CARD_EN)
> -		sdhci_writew(host, clk & ~SDHCI_CLOCK_CARD_EN,
> -			SDHCI_CLOCK_CONTROL);
> +	sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
>  
> -	if (clock == 0) {
> -		sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
> +	if (clock == 0)
>  		return;
> -	}
>  
>  	clk = sdhci_calc_clk(host, clock, &host->mmc->actual_clock);
>  	sdhci_enable_clk(host, clk);