linux-kernel - Re: [PATCH 1/3] mmc: core: need do mmc_power_cycle in mmc_sdio_resend_if

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: <20200420191518.GG199755@google.com>
Date:   Mon, 20 Apr 2020 12:15:18 -0700
From:   Matthias Kaehlcke <mka@...omium.org>
To:     Yong Mao <yong.mao@...iatek.com>
Cc:     Ulf Hansson <ulf.hansson@...aro.org>,
        Chaotian Jing <chaotian.jing@...iatek.com>,
        Matthias Brugger <matthias.bgg@...il.com>,
        linux-mmc@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-mediatek@...ts.infradead.org, linux-kernel@...r.kernel.org,
        srv_heupstream@...iatek.com
Subject: Re: [PATCH 1/3] mmc: core: need do mmc_power_cycle in
 mmc_sdio_resend_if_cond

Hi,

On Tue, Apr 14, 2020 at 11:40:09AM +0800, Yong Mao wrote:
> From: yong mao <yong.mao@...iatek.com>
> 
> When mmc_sdio_resned_if_cond is invoked, it indicates the SDIO
> device is not in the right state. In this condition, the previous
> implementation of mmc_sdio_resend_if_cond can't make sure SDIO
> device be back to idle state. mmc_power_cycle can reset the SDIO
> device by HW and also make sure SDIO device enter to idle state
> correctly.
> 
> Signed-off-by: Yong Mao <yong.mao@...iatek.com>
> ---
>  drivers/mmc/core/sdio.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
> index ebb387a..ada0a80 100644
> --- a/drivers/mmc/core/sdio.c
> +++ b/drivers/mmc/core/sdio.c
> @@ -546,6 +546,7 @@ static int mmc_sdio_init_uhs_card(struct mmc_card *card)
>  static void mmc_sdio_resend_if_cond(struct mmc_host *host,
>  				    struct mmc_card *card)
>  {
> +	mmc_power_cycle(host, host->card->ocr);

My MMC/SDIO background is limited, but it seems this isn't needed for the
vast majority of SDIO devices, otherwise it probably would have been added
earlier. I wonder if it would make sense to make the power cycle
conditional through a quirk, to limit it to the devices that need it.

>  	sdio_reset(host);
>  	mmc_go_idle(host);
>  	mmc_send_if_cond(host, host->ocr_avail);
> -- 
> 1.9.1