From: Johan Hovold <johan@kernel.org>
To: Guangshuo Li <lgs201920130244@gmail.com>
Cc: "Andreas Klinger" <ak@it-klinger.de>,
"Jonathan Cameron" <jic23@kernel.org>,
"David Lechner" <dlechner@baylibre.com>,
"Nuno Sá" <nuno.sa@analog.com>,
"Andy Shevchenko" <andy@kernel.org>,
linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iio: proximity: srf04: fix runtime PM autosuspend cleanup
Date: Tue, 18 Aug 2026 09:14:15 +0200 [thread overview]
Message-ID: <aoQGR8uSXXmOxnWI@hovoldconsulting.com> (raw)
In-Reply-To: <20260807141938.2491195-1-lgs201920130244@gmail.com>
On Fri, Aug 07, 2026 at 10:19:37PM +0800, Guangshuo Li wrote:
> srf04_probe() calls pm_runtime_use_autosuspend() when the optional
> power GPIO is present, but srf04_remove() does not call the matching
> pm_runtime_dont_use_autosuspend() before disabling runtime PM.
>
> The runtime PM documentation requires pm_runtime_use_autosuspend() to
> be balanced with pm_runtime_dont_use_autosuspend() when the driver is
> removed. Failing to do so can leave the autosuspend usage state
> unbalanced and may result in a usage_count leak when the autosuspend
> delay is negative.
I believe the term "leak" here is misleading as the usage count would be
dropped again when the user re-enables autosuspend through sysfs, right?
That said, drivers should clean up after themselves so disabling
autosuspend is still the right to do. But it's more of a cleanup than a
fix (and does not need to be backported).
Johan
next prev parent reply other threads:[~2026-08-18 7:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-07 14:19 [PATCH] iio: proximity: srf04: fix runtime PM autosuspend cleanup Guangshuo Li
2026-08-07 15:02 ` Joshua Crofts
2026-08-18 7:07 ` Johan Hovold
2026-08-07 23:41 ` Jonathan Cameron
2026-08-18 7:14 ` Johan Hovold [this message]
2026-08-22 0:08 ` Jonathan Cameron
2026-08-24 12:32 ` Johan Hovold
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