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Message-ID: <d048f863-05d1-4aeb-8904-4c09ecbe55d9@arm.com>
Date: Wed, 3 Apr 2024 13:43:59 +0100
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Subject: Re: [PATCH v2 1/3] thermal: gov_power_allocator: Allow binding
 without cooling devices
Content-Language: en-US
To: Nikita Travkin <nikitos.tr@gmail.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
 "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>, linux-pm@vger.kernel.org,
 Daniel Lezcano <daniel.lezcano@linaro.org>, linux-kernel@vger.kernel.org,
 Zhang Rui <rui.zhang@intel.com>
References: <20240403-gpa-no-cooling-devs-v2-0-79bdd8439449@trvn.ru>
 <20240403-gpa-no-cooling-devs-v2-1-79bdd8439449@trvn.ru>
From: Lukasz Luba <lukasz.luba@arm.com>
In-Reply-To: <20240403-gpa-no-cooling-devs-v2-1-79bdd8439449@trvn.ru>
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On 4/3/24 12:31, Nikita Travkin via B4 Relay wrote:
> From: Nikita Travkin <nikita@trvn.ru>
> 
> IPA was recently refactored to split out memory allocation into a
> separate funciton. That funciton was made to return -EINVAL if there is
> zero power_actors and thus no memory to allocate. This causes IPA to
> fail probing when the thermal zone has no attached cooling devices.
> 
> Since cooling devices can attach after the thermal zone is created and
> the governer is attached to it, failing probe due to the lack of cooling
> devices is incorrect.
> 
> Change the allocate_actors_buffer() to return success when there is no
> cooling devices present.
> 
> Fixes: 912e97c67cc3 ("thermal: gov_power_allocator: Move memory allocation out of throttle()")
> Signed-off-by: Nikita Travkin <nikita@trvn.ru>
> ---
>   drivers/thermal/gov_power_allocator.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c
> index 1b17dc4c219c..ec637071ef1f 100644
> --- a/drivers/thermal/gov_power_allocator.c
> +++ b/drivers/thermal/gov_power_allocator.c
> @@ -606,7 +606,7 @@ static int allocate_actors_buffer(struct power_allocator_params *params,
>   
>   	/* There might be no cooling devices yet. */
>   	if (!num_actors) {
> -		ret = -EINVAL;
> +		ret = 0;
>   		goto clean_state;
>   	}
>   
> 

LGTM

Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>