From: Frederic Weisbecker <fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: Jonathan Cameron <jic23-KWPb1pKIrIJaa/9Udqfwiw@public.gmane.org>
Cc: LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Zhang Rui <rui.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>,
Rodolfo Giometti
<giometti-AVVDYK/kqiJWk0Htik3J/w@public.gmane.org>,
"Michele De Candia (VT)"
<michele.decandia-EZxuzQJkuwwybS5Ee8rs3A@public.gmane.org>,
Linux I2C <linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH V2] ALS: TSL2550 driver move from i2c/chips
Date: Sat, 17 Oct 2009 19:07:20 +0200 [thread overview]
Message-ID: <20091017170718.GB10344@nowhere> (raw)
In-Reply-To: <4AD9F750.9090800-KWPb1pKIrIJaa/9Udqfwiw@public.gmane.org>
On Sat, Oct 17, 2009 at 05:56:48PM +0100, Jonathan Cameron wrote:
> +static int tsl2550_get_id(void)
> +{
> + int ret, val;
> +
> +idr_again:
> + if (unlikely(idr_pre_get(&tsl2550_idr, GFP_KERNEL) == 0))
> + return -ENOMEM;
> + spin_lock(&tsl2550_idr_lock);
> + ret = idr_get_new(&tsl2550_idr, NULL, &val);
> + if (unlikely(ret == -EAGAIN))
> + goto idr_again;
That looks like a fair chance to produce a deadlock
by reacquiring the above spinlock.
Also I never see the above lock released later from this
function or its caller.
WARNING: multiple messages have this Message-ID (diff)
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Jonathan Cameron <jic23@cam.ac.uk>
Cc: LKML <linux-kernel@vger.kernel.org>,
Zhang Rui <rui.zhang@intel.com>,
Jean Delvare <khali@linux-fr.org>,
Rodolfo Giometti <giometti@enneenne.com>,
"Michele De Candia (VT)" <michele.decandia@valueteam.com>,
Linux I2C <linux-i2c@vger.kernel.org>
Subject: Re: [PATCH V2] ALS: TSL2550 driver move from i2c/chips
Date: Sat, 17 Oct 2009 19:07:20 +0200 [thread overview]
Message-ID: <20091017170718.GB10344@nowhere> (raw)
In-Reply-To: <4AD9F750.9090800@cam.ac.uk>
On Sat, Oct 17, 2009 at 05:56:48PM +0100, Jonathan Cameron wrote:
> +static int tsl2550_get_id(void)
> +{
> + int ret, val;
> +
> +idr_again:
> + if (unlikely(idr_pre_get(&tsl2550_idr, GFP_KERNEL) == 0))
> + return -ENOMEM;
> + spin_lock(&tsl2550_idr_lock);
> + ret = idr_get_new(&tsl2550_idr, NULL, &val);
> + if (unlikely(ret == -EAGAIN))
> + goto idr_again;
That looks like a fair chance to produce a deadlock
by reacquiring the above spinlock.
Also I never see the above lock released later from this
function or its caller.
next prev parent reply other threads:[~2009-10-17 17:07 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-17 16:56 [PATCH V2] ALS: TSL2550 driver move from i2c/chips Jonathan Cameron
2009-10-17 16:56 ` Jonathan Cameron
[not found] ` <4AD9F750.9090800-KWPb1pKIrIJaa/9Udqfwiw@public.gmane.org>
2009-10-17 17:07 ` Frederic Weisbecker [this message]
2009-10-17 17:07 ` Frederic Weisbecker
2009-10-17 17:17 ` Jonathan Cameron
2009-10-17 17:17 ` Jonathan Cameron
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