From: Thomas Gleixner <tglx@linutronix.de>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Lars-Peter Clausen <lars@metafoo.de>
Cc: Jonathan Cameron <jic23@kernel.org>,
Hartmut Knaack <knaack.h@gmx.de>,
Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
Christian Eggers <ceggers@arri.de>,
linux-iio@vger.kernel.org
Subject: Re: [PATCH 1/2] iio: hrtimer-trigger: Mark hrtimer to expire in hard interrupt context
Date: Thu, 13 Aug 2020 14:19:57 +0200 [thread overview]
Message-ID: <877du2louq.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20200813112741.grdytusuwrlskpwa@linutronix.de>
Sebastian Andrzej Siewior <bigeasy@linutronix.de> writes:
> On 2020-08-13 11:46:30 [+0200], Lars-Peter Clausen wrote:
>> If you are running with forced IRQ threads the only thing that will then
>> happen in the actual hard IRQ context is the launching of the IRQ threads.
>> Th e IRQ handler of the device driver will run in a threaded IRQ.
>
> So if it is really just the wakeup of the IRQ-thread then it should be
> okay.
> One thing: iio_trigger_poll() may invoke iio_trigger_notify_done(). This
> would invoke trig->ops->try_reenable callback if available.
> I grepped and found
> - bma180_trig_try_reen()
> It appears to perform i2c_smbus_read_byte_data() and smbus sounds
> sleeping. I don't know if it attempts to acquire any spinlock_t but it
> will be wrong on RT.
It's wrong even on !RT. i2c reads cannot be invoked from hard interrupt
context.
next prev parent reply other threads:[~2020-08-13 12:20 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-13 7:53 [PATCH 1/2] iio: hrtimer-trigger: Mark hrtimer to expire in hard interrupt context Lars-Peter Clausen
2020-08-13 7:53 ` [PATCH 2/2] iio: sysfs-trigger: Mark irq_work to expire in hardirq context Lars-Peter Clausen
2020-08-13 9:11 ` [PATCH 1/2] iio: hrtimer-trigger: Mark hrtimer to expire in hard interrupt context Sebastian Andrzej Siewior
2020-08-13 9:46 ` Lars-Peter Clausen
2020-08-13 11:27 ` Sebastian Andrzej Siewior
2020-08-13 12:19 ` Thomas Gleixner [this message]
2020-08-13 14:55 ` Jonathan Cameron
2020-08-14 5:24 ` Lars-Peter Clausen
2020-08-14 10:30 ` Jonathan Cameron
2020-09-20 18:15 ` Jonathan Cameron
2020-09-21 7:17 ` Christian Eggers
2020-09-21 9:57 ` Jonathan Cameron
2020-09-21 12:27 ` Sebastian Andrzej Siewior
2020-09-21 13:32 ` Jonathan Cameron
2020-09-22 2:51 ` Andy Duan
2020-09-24 6:41 ` Sanchayan Maity
2020-09-24 8:54 ` Stefan Agner
2020-09-25 12:42 ` Jonathan Cameron
2020-10-02 14:10 ` Christian Eggers
2020-10-10 13:23 ` Jonathan Cameron
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