Re: [PATCH] mmc: core: Fix bug on signal voltage switch failure

[Adrian Hunter]

On 31/03/16 17:17, Naveen Kumar Parna wrote:
> When switching SD and SDIO cards from 3.3V to 1.8V signal level fails, a bug in sdhci_set_power() will trigger.
> To fix the kernel crash during recovery from signal voltage switch failure, OCR should be reset to avail voltage mask before power-cycle the card.
> 
> Signed-off-by: Naveen Kumar Parna <naveenkumar.parna@xxxxxxxxx>
> ---
>  drivers/mmc/core/core.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index f26a5f1..e7eb427 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -1477,6 +1477,8 @@ power_cycle:
>  	if (err) {
>  		pr_debug("%s: Signal voltage switch failed, "
>  			"power cycling card\n", mmc_hostname(host));
> +		/* Reset OCR mask */
> +		ocr =  host->ocr_avail;
>  		mmc_power_cycle(host, ocr);
>  	}
>  
> 


Is this the same as the following?


commit d9bfbb95ed598a09cf336adb0f190ee0ff802f0d
Author: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Date:   Thu Nov 26 14:00:47 2015 +0200

    mmc: sdio: Fix invalid vdd in voltage switch power cycle

    The 'ocr' parameter passed to mmc_set_signal_voltage()
    defines the power-on voltage used when power cycling
    after a failure to set the voltage.  However, in the
    case of mmc_sdio_init_card(), the value passed has the
    R4_18V_PRESENT flag set which is not valid for power-on
    and results in an invalid vdd.  Fix by passing the card's
    ocr value which does not have the flag.

    Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
    Cc: stable@xxxxxxxxxxxxxxx # v3.13+
    Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>