linux-kernel - Re: [PATCH RFC] iio: pressure: zpa2326: report interrupted case as 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]

Date:   Sun, 14 May 2017 11:46:58 +0200 (CEST)
From:   Peter Meerwald-Stadler <pmeerw@...erw.net>
To:     Nicholas Mc Guire <der.herr@...r.at>
cc:     Jonathan Cameron <jic23@...nel.org>,
        Hartmut Knaack <knaack.h@....de>,
        Lars-Peter Clausen <lars@...afoo.de>,
        simran singhal <singhalsimran0@...il.com>,
        Arnd Bergmann <arnd@...db.de>,
        Gregor Boirie <gregor.boirie@...rot.com>,
        linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH RFC] iio: pressure: zpa2326: report interrupted case as
 failure


> If the timeout-case prints a warning message then probably the interrupted
> case should also. Further, wait_for_completion_interruptible_timeout()
> returns long not int. 
> 
> Fixes: commit 03b262f2bbf4 ("iio:pressure: initial zpa2326 barometer support")
> Signed-off-by: Nicholas Mc Guire <der.herr@...r.at>

this is actually a v2, looks good to me

> ---
> 
> The original control-flow was technically not wrong just confusing and a bit 
> complicated. Not clear if reporting the interrupted case actually is useful,
> but given that the timeout is relatively long (200ms) it is not that unlikely
> so differentiating the cases seems helpful.
> 
> Patch was compile-tested with: x86_64_defconfig + CONFIG_IIO=m, CONFIG_ZPA2326=m
> 
> Patch is against v4.11 (localversion-next is next-20170512)
> 
>  drivers/iio/pressure/zpa2326.c | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/iio/pressure/zpa2326.c b/drivers/iio/pressure/zpa2326.c
> index e58a0ad..617926f 100644
> --- a/drivers/iio/pressure/zpa2326.c
> +++ b/drivers/iio/pressure/zpa2326.c
> @@ -867,12 +867,13 @@ static int zpa2326_wait_oneshot_completion(const struct iio_dev   *indio_dev,
>  {
>  	int          ret;
>  	unsigned int val;
> +	long     timeout;
>  
>  	zpa2326_dbg(indio_dev, "waiting for one shot completion interrupt");
>  
> -	ret = wait_for_completion_interruptible_timeout(
> +	timeout = wait_for_completion_interruptible_timeout(
>  		&private->data_ready, ZPA2326_CONVERSION_JIFFIES);
> -	if (ret > 0)
> +	if (timeout > 0)
>  		/*
>  		 * Interrupt handler completed before timeout: return operation
>  		 * status.
> @@ -882,13 +883,15 @@ static int zpa2326_wait_oneshot_completion(const struct iio_dev   *indio_dev,
>  	/* Clear all interrupts just to be sure. */
>  	regmap_read(private->regmap, ZPA2326_INT_SOURCE_REG, &val);
>  
> -	if (!ret)
> +	if (!timeout) {
>  		/* Timed out. */
> +		zpa2326_warn(indio_dev, "no one shot interrupt occurred (%ld)",
> +			     timeout);
>  		ret = -ETIME;
> -
> -	if (ret != -ERESTARTSYS)
> -		zpa2326_warn(indio_dev, "no one shot interrupt occurred (%d)",
> -			     ret);
> +	} else if (timeout < 0) {
> +		zpa2326_warn(indio_dev, "wait for one shot interrupt canceled");
> +		ret = -ERESTARTSYS;
> +	}
>  
>  	return ret;
>  }
> 

-- 

Peter Meerwald-Stadler
Mobile: +43 664 24 44 418