Re: [V9 7/9] drm/amd/pm: add flood detection for wbrf events

Lazar, Lijo
2023-08-18T09:50:26Z

On 8/18/2023 8:56 AM, Evan Quan wrote:
> To protect PMFW from being overloaded.
>
> Signed-off-by: Evan Quan <evan.quan@amd.com>
> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c | 31 +++++++++++++++----
> drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h | 7 +++++
> 2 files changed, 32 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> index 704442ce1da3..6c8bcdc17a15 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> @@ -1318,7 +1318,8 @@ static int smu_wbrf_event_handler(struct notifier_block *nb,
>
> switch (action) {
> case WBRF_CHANGED:
> - smu_wbrf_handle_exclusion_ranges(smu);
> + schedule_delayed_work(&smu->wbrf_delayed_work,
> + msecs_to_jiffies(SMU_WBRF_EVENT_HANDLING_PACE));
> break;
> default:
> return NOTIFY_DONE;
> @@ -1327,6 +1328,21 @@ static int smu_wbrf_event_handler(struct notifier_block *nb,
> return NOTIFY_OK;
> }
>
> +/**
> + * 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);
> +}
> +
> /**
> * smu_wbrf_support_check - check wbrf support
> *
> @@ -1357,12 +1373,14 @@ static void smu_wbrf_support_check(struct smu_context *smu)
> */
> static int smu_wbrf_init(struct smu_context *smu)
> {
> - struct amdgpu_device *adev = smu->adev;
> int ret;
>
> if (!smu->wbrf_supported)
> return 0;
>
> + INIT_DELAYED_WORK(&smu->wbrf_delayed_work,
> + smu_wbrf_delayed_work_handler);
> +

This is one-time and can be part of sw_init.

Thanks,
Lijo

> smu->wbrf_notifier.notifier_call = smu_wbrf_event_handler;
> ret = wbrf_register_notifier(&smu->wbrf_notifier);
> if (ret)
> @@ -1373,11 +1391,10 @@ 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;
> }
>
> /**
> @@ -1393,6 +1410,8 @@ static void smu_wbrf_fini(struct smu_context *smu)
> return;
>
> wbrf_unregister_notifier(&smu->wbrf_notifier);
> +
> + 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 244297979f92..4d5cb1b511e5 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
> +++ b/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
> @@ -480,6 +480,12 @@ 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;
> @@ -581,6 +587,7 @@ struct smu_context
> /* data structures for wbrf feature support */
> bool wbrf_supported;
> struct notifier_block wbrf_notifier;
> + struct delayed_work wbrf_delayed_work;
> };
>
> struct i2c_adapter;