linux-kernel - Re: [PATCH V3 5/7] drm/amd/pm: add flood detection for wbrf events

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Message-ID: <83f35ea2-935e-3026-908e-74a5147b22f8@amd.com>
Date:   Sun, 18 Jun 2023 21:22:58 -0500
From:   Mario Limonciello <mario.limonciello@....com>
To:     Evan Quan <evan.quan@....com>, rafael@...nel.org, lenb@...nel.org,
        Alexander.Deucher@....com, Christian.Koenig@....com,
        Xinhui.Pan@....com, airlied@...il.com, daniel@...ll.ch,
        kvalo@...nel.org, nbd@....name, lorenzo@...nel.org,
        ryder.lee@...iatek.com, shayne.chen@...iatek.com,
        sean.wang@...iatek.com, matthias.bgg@...il.com,
        angelogioacchino.delregno@...labora.com, Lijo.Lazar@....com
Cc:     linux-kernel@...r.kernel.org, linux-acpi@...r.kernel.org,
        amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        linux-wireless@...r.kernel.org
Subject: Re: [PATCH V3 5/7] drm/amd/pm: add flood detection for wbrf events

On 6/16/23 01:57, Evan Quan wrote:
> To protect PMFW from being overloaded.
> 
> Signed-off-by: Evan Quan <evan.quan@....com>
Reviewed-by: Mario Limonciello <mario.limonciello@....com>
> ---
>   drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c     | 28 ++++++++++++++++---
>   drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h |  7 +++++
>   2 files changed, 31 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> index 89f876cc60e6..2619e310ef54 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> @@ -1272,6 +1272,22 @@ static void smu_wbrf_event_handler(struct amdgpu_device *adev)
>   {
>   	struct smu_context *smu = adev->powerplay.pp_handle;
>   
> +	schedule_delayed_work(&smu->wbrf_delayed_work,
> +			      msecs_to_jiffies(SMU_WBRF_EVENT_HANDLING_PACE));
> +}
> +
> +/**
> + * smu_wbrf_delayed_work_handler - callback on delayed work timer expired
> + *
> + * @work: struct work_struct pointer
> + *
> + * Flood is over and driver will consume the latest exclusion ranges.
> + */
> +static void smu_wbrf_delayed_work_handler(struct work_struct *work)
> +{
> +	struct smu_context *smu =
> +		container_of(work, struct smu_context, wbrf_delayed_work.work);
> +
>   	smu_wbrf_handle_exclusion_ranges(smu);
>   }
>   
> @@ -1311,6 +1327,9 @@ static int smu_wbrf_init(struct smu_context *smu)
>   	if (!smu->wbrf_supported)
>   		return 0;
>   
> +	INIT_DELAYED_WORK(&smu->wbrf_delayed_work,
> +			  smu_wbrf_delayed_work_handler);
> +
>   	ret = amdgpu_acpi_register_wbrf_notify_handler(adev,
>   						       smu_wbrf_event_handler);
>   	if (ret)
> @@ -1321,11 +1340,10 @@ static int smu_wbrf_init(struct smu_context *smu)
>   	 * before our driver loaded. To make sure our driver
>   	 * is awared of those exclusion ranges.
>   	 */
> -	ret = smu_wbrf_handle_exclusion_ranges(smu);
> -	if (ret)
> -		dev_err(adev->dev, "Failed to handle wbrf exclusion ranges\n");
> +	schedule_delayed_work(&smu->wbrf_delayed_work,
> +			      msecs_to_jiffies(SMU_WBRF_EVENT_HANDLING_PACE));
>   
> -	return ret;
> +	return 0;
>   }
>   
>   /**
> @@ -1343,6 +1361,8 @@ static void smu_wbrf_fini(struct smu_context *smu)
>   		return;
>   
>   	amdgpu_acpi_unregister_wbrf_notify_handler(adev);
> +
> +	cancel_delayed_work_sync(&smu->wbrf_delayed_work);
>   }
>   
>   static int smu_smc_hw_setup(struct smu_context *smu)
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h b/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
> index ff0af3da0be2..aa63cc43d41c 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
> +++ b/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
> @@ -478,6 +478,12 @@ struct stb_context {
>   
>   #define WORKLOAD_POLICY_MAX 7
>   
> +/*
> + * Configure wbrf event handling pace as there can be only one
> + * event processed every SMU_WBRF_EVENT_HANDLING_PACE ms.
> + */
> +#define SMU_WBRF_EVENT_HANDLING_PACE	10
> +
>   struct smu_context
>   {
>   	struct amdgpu_device            *adev;
> @@ -576,6 +582,7 @@ struct smu_context
>   
>   	/* data structures for wbrf feature support */
>   	bool				wbrf_supported;
> +	struct delayed_work		wbrf_delayed_work;
>   };
>   
>   struct i2c_adapter;