From: Jonathan Cameron <jic23@kernel.org>
To: Peter Rosin <peda@axentia.se>
Cc: Rasmus Villemoes <ravi@prevas.dk>,
Guenter Roeck <linux@roeck-us.net>,
linux-iio@vger.kernel.org, linux-hwmon@vger.kernel.org
Subject: Re: lockdep splat involving iio-hwmon and iio-rescale drivers
Date: Sun, 14 Dec 2025 14:39:30 +0000 [thread overview]
Message-ID: <20251214143930.6ee61d75@jic23-huawei> (raw)
In-Reply-To: <98101700-35EB-4D45-AEE4-6FF1E9D55505@axentia.se>
On Sun, 14 Dec 2025 05:56:14 +0100
Peter Rosin <peda@axentia.se> wrote:
> On December 13, 2025 5:57:23 PM GMT+01:00, Jonathan Cameron <jic23@kernel.org> wrote:
> > I'm a bit curious we haven't seen many reports of this one. Whilst
> > there are relatively few IIO drivers that consume other IIO driver
> > provided channels it's also not a particularly new thing.
>
> I suspect the reason is that plain old iio_read_channel_raw does not
> grab the info_exist_lock, so it seems that you need two levels of
> iio_read_channel_processed[_scale] (or something like that). Which
> is rarer still.
iio_read_channel_raw() does grab the lock (you had me worried
there for a moment!) Does it with a guard() so perhaps that threw you
off.
Jonathan
>
> Cheers,
> Peter
next prev parent reply other threads:[~2025-12-14 14:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-10 14:31 lockdep splat involving iio-hwmon and iio-rescale drivers Rasmus Villemoes
2025-12-10 19:12 ` Guenter Roeck
2025-12-10 22:54 ` Peter Rosin
2025-12-10 23:29 ` Peter Rosin
2025-12-12 13:12 ` Rasmus Villemoes
2025-12-13 16:57 ` Jonathan Cameron
[not found] ` <98101700-35EB-4D45-AEE4-6FF1E9D55505@axentia.se>
2025-12-14 14:39 ` Jonathan Cameron [this message]
2025-12-15 9:14 ` Rasmus Villemoes
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