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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <56FE2344.6060702@intel.com>
Date:	Fri, 1 Apr 2016 10:29:08 +0300
From:	Adrian Hunter <adrian.hunter@...el.com>
To:	Naveen Kumar Parna <naveenkumar.parna@...il.com>,
	ulf.hansson@...aro.org, chris@...ntf.net
Cc:	linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mmc: core: Fix bug on signal voltage switch failure

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@...il.com>
> ---
>  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@...el.com>
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@...el.com>
    Cc: stable@...r.kernel.org # v3.13+
    Signed-off-by: Ulf Hansson <ulf.hansson@...aro.org>