linux-kernel - Re: [PATCH v9 3/3] firmware: qcom_scm: Use TASK_IDLE state in wait_for_wq

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Message-ID: <CAMRc=MfB6c=Fpxuapq9JXpGnFnx2SxpKjVk5yQNXFdtNF7FYZQ@mail.gmail.com>
Date: Tue, 25 Nov 2025 06:15:50 -0800
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Shivendra Pratap <shivendra.pratap@....qualcomm.com>
Cc: linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Unnathi Chalicheemala <unnathi.chalicheemala@....qualcomm.com>, 
	Bjorn Andersson <andersson@...nel.org>, Konrad Dybcio <konradybcio@...nel.org>
Subject: Re: [PATCH v9 3/3] firmware: qcom_scm: Use TASK_IDLE state in wait_for_wq_completion()

On Sun, 23 Nov 2025 15:19:32 +0100, Shivendra Pratap
<shivendra.pratap@....qualcomm.com> said:
> From: Unnathi Chalicheemala <unnathi.chalicheemala@....qualcomm.com>
>
> When the kernel issues an SMC (Secure Monitor Call) and the firmware
> requests the kernel to wait, the waiting thread enters an
> uninterruptible (D) state. In case of an extended wait request by the
> firmware, any device suspend request, cannot proceed because of the
> thread stuck in D state. This blocks the device suspend.
>
> Replace wait_for_completion() with wait_for_completion_state(...,
> TASK_IDLE), so that the waiting thread, show up in TASK_IDLE state,
> instead of TASK_UNINTERRUPTIBLE (D state). This allows the thread to
> block until completion, without blocking the device suspend.
>
> Signed-off-by: Unnathi Chalicheemala <unnathi.chalicheemala@....qualcomm.com>
> Signed-off-by: Shivendra Pratap <shivendra.pratap@....qualcomm.com>
> ---
>  drivers/firmware/qcom/qcom_scm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
> index 149c2ccec2a5ff77054178fa021fd0b721d9f8d7..dfe0410fa9f965b16f8b0a9d98f3046e80b8b97b 100644
> --- a/drivers/firmware/qcom/qcom_scm.c
> +++ b/drivers/firmware/qcom/qcom_scm.c
> @@ -2320,7 +2320,7 @@ int qcom_scm_wait_for_wq_completion(u32 wq_ctx)
>  	if (IS_ERR(wq))
>  		return PTR_ERR(wq);
>
> -	wait_for_completion(wq);
> +	wait_for_completion_state(wq, TASK_IDLE);
>
>  	return 0;
>  }
>
> --
> 2.34.1
>

Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>