linux-kernel - Re: [RESEND PATCH] mmc: sdhci: fix wakeup configuration

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20160513131714.GA18460@odux.rfo.atmel.com>
Date:	Fri, 13 May 2016 15:17:14 +0200
From:	Ludovic Desroches <ludovic.desroches@...el.com>
To:	<adrian.hunter@...el.com>, <ulf.hansson@...aro.org>
CC:	<linux-mmc@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<nicolas.ferre@...el.com>, <kliu5@...vell.com>, <jlfu@...vell.com>,
	<jszhang@...vell.com>,
	Ludovic Desroches <ludovic.desroches@...el.com>
Subject: Re: [RESEND PATCH] mmc: sdhci: fix wakeup configuration

Mistake while sending v2, sorry for the noise.

On Fri, May 13, 2016 at 03:14:46PM +0200, Ludovic Desroches wrote:
> Activating wakeup event is not enough to get a wakeup signal. The
> corresponding events have to be enabled in the Interrupt Status Enable
> Register too.
> 
> Signed-off-by: Ludovic Desroches <ludovic.desroches@...el.com>
> ---
> Hi,
> 
> I just updated sdhci_enable_irq_wakeups() not sdhci_disable_irq_wakeups()
> because I don't think it is necessary to configure SDHCI_INT_ENABLE at this
> step, it will be done with sdhci_init() or sdhci_enable_card_detection().
> 
> While I was writing this patch, several questions came to my mind:
> - Is the naming correct? wakeup signal is not an irq. 'enable_irq_wakeups' can
>   be a bit confusing.
> - If we want to wakeup from irq, we may have to set SDHCI_INT_ENABLE and
>   SDHCI_SIGNAL_ENABLE and not rely on a previous configuration, isn't it?
> 
> Regards
> 
> Ludovic
> 
>  drivers/mmc/host/sdhci.c | 26 ++++++++++++++++++--------
>  1 file changed, 18 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index b284924..6fc69ed 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2638,18 +2638,28 @@ static irqreturn_t sdhci_thread_irq(int irq, void *dev_id)
>  \*****************************************************************************/
>  
>  #ifdef CONFIG_PM
> +/*
> + * To enable wakeup events, the corresponding events have to be enabled in
> + * the Interrupt Status Enable register too. See 'Table 1-6: Wakeup Signal
> + * Table' in the SD Host Controller Standard Specification.
> + */
>  void sdhci_enable_irq_wakeups(struct sdhci_host *host)
>  {
> -	u8 val;
> -	u8 mask = SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE
> -			| SDHCI_WAKE_ON_INT;
> +	u8 wakeup_val;
> +	u8 wakeup_mask = SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE |
> +			 SDHCI_WAKE_ON_INT;
> +	u32 irq_val = SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE |
> +		      SDHCI_INT_CARD_INT;
>  
> -	val = sdhci_readb(host, SDHCI_WAKE_UP_CONTROL);
> -	val |= mask ;
> +	wakeup_val = sdhci_readb(host, SDHCI_WAKE_UP_CONTROL);
> +	wakeup_val |= wakeup_mask;
>  	/* Avoid fake wake up */
> -	if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION)
> -		val &= ~(SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE);
> -	sdhci_writeb(host, val, SDHCI_WAKE_UP_CONTROL);
> +	if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) {
> +		wakeup_val &= ~(SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE);
> +		irq_val &= ~(SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE);
> +	}
> +	sdhci_writeb(host, wakeup_val, SDHCI_WAKE_UP_CONTROL);
> +	sdhci_writel(host, irq_val, SDHCI_INT_ENABLE);
>  }
>  EXPORT_SYMBOL_GPL(sdhci_enable_irq_wakeups);
>  
> -- 
> 2.5.0
>