Re: [PATCH 1/2] i3c: dw: remove redundant pm_runtime_dont_use_autosuspend() calls

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found no new issues
in this patch, but noticed 1 related pre-existing issue it does not
introduce:
- [Medium] i3c: master: dw: clock enable count underflow in
  dw_i3c_common_remove() [1]
--

commit 4f7b7a8b26800680d2cdbe5fe6acbbf1f93c63ec
Author: Joshua Crofts <crofts@kernel.org>

i3c: dw: remove redundant pm_runtime_dont_use_autosuspend() calls

This commit removes redundant pm_runtime_dont_use_autosuspend() calls from
dw_i3c_common_probe() and dw_i3c_common_remove().

> diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
> index d1119f203d1b6..f8fed797e0e4d 100644
> --- a/drivers/i3c/master/dw-i3c-master.c
> +++ b/drivers/i3c/master/dw-i3c-master.c

[ ... ]

> @@ -1792,7 +1791,6 @@ void dw_i3c_common_remove(struct dw_i3c_master *master)
>  
>  	pm_runtime_disable(master->dev);
>  	pm_runtime_set_suspended(master->dev);
> -	pm_runtime_dont_use_autosuspend(master->dev);
>  }
>  EXPORT_SYMBOL_GPL(dw_i3c_common_remove);

[Severity: Medium]
This problem wasn't introduced by this patch, but can unbinding a
runtime-suspended controller underflow the clock enable counts [1]?

dw_i3c_common_probe() acquires core_clk and pclk via
devm_clk_get_optional_enabled(), which registers a devres action to call
clk_disable_unprepare() on removal.  However,
dw_i3c_master_runtime_suspend() also disables these clocks via
dw_i3c_master_disable_clks().  If the device is runtime-suspended when
dw_i3c_common_remove() disables runtime PM without resuming the device,
devres will disable the already-disabled clocks and trigger a clock
enable count underflow warning.

[1] https://sashiko.dev/#/bug/linux-2e78b07f-df35-42bd-b4ae-71873b79b67f

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261107-dont-use-autosuspend-i3c-v1-0-80a1546354ce@kernel.org?part=1

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