Re: [PATCH] accel/ivpu: Correct DCT interrupt handling

[Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>]

Applied to drm-misc-fixes

On 4/16/2025 12:26 PM, Maciej Falkowski wrote:
> From: Karol Wachowski <karol.wachowski@intel.com>
> 
> Fix improper use of dct_active_percent field in DCT interrupt handler
> causing DCT to never get enabled. Set dct_active_percent internally before
> IPC to ensure correct driver value even if IPC fails.
> Set default DCT value to 30 accordingly to HW architecture specification.
> 
> Fixes: a19bffb10c46 ("accel/ivpu: Implement DCT handling")
> Signed-off-by: Karol Wachowski <karol.wachowski@intel.com>
> Signed-off-by: Maciej Falkowski <maciej.falkowski@linux.intel.com>
> ---
>  drivers/accel/ivpu/ivpu_hw_btrs.h |  2 +-
>  drivers/accel/ivpu/ivpu_pm.c      | 18 ++++++++++--------
>  2 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/accel/ivpu/ivpu_hw_btrs.h b/drivers/accel/ivpu/ivpu_hw_btrs.h
> index 300f749971d4..d2d82651976d 100644
> --- a/drivers/accel/ivpu/ivpu_hw_btrs.h
> +++ b/drivers/accel/ivpu/ivpu_hw_btrs.h
> @@ -14,7 +14,7 @@
>  #define PLL_PROFILING_FREQ_DEFAULT   38400000
>  #define PLL_PROFILING_FREQ_HIGH      400000000
>  
> -#define DCT_DEFAULT_ACTIVE_PERCENT 15u
> +#define DCT_DEFAULT_ACTIVE_PERCENT 30u
>  #define DCT_PERIOD_US		   35300u
>  
>  int ivpu_hw_btrs_info_init(struct ivpu_device *vdev);
> diff --git a/drivers/accel/ivpu/ivpu_pm.c b/drivers/accel/ivpu/ivpu_pm.c
> index 1fe03fc16bbc..ea30db181cd7 100644
> --- a/drivers/accel/ivpu/ivpu_pm.c
> +++ b/drivers/accel/ivpu/ivpu_pm.c
> @@ -448,16 +448,17 @@ int ivpu_pm_dct_enable(struct ivpu_device *vdev, u8 active_percent)
>  	active_us = (DCT_PERIOD_US * active_percent) / 100;
>  	inactive_us = DCT_PERIOD_US - active_us;
>  
> +	vdev->pm->dct_active_percent = active_percent;
> +
> +	ivpu_dbg(vdev, PM, "DCT requested %u%% (D0: %uus, D0i2: %uus)\n",
> +		 active_percent, active_us, inactive_us);
> +
>  	ret = ivpu_jsm_dct_enable(vdev, active_us, inactive_us);
>  	if (ret) {
>  		ivpu_err_ratelimited(vdev, "Failed to enable DCT: %d\n", ret);
>  		return ret;
>  	}
>  
> -	vdev->pm->dct_active_percent = active_percent;
> -
> -	ivpu_dbg(vdev, PM, "DCT set to %u%% (D0: %uus, D0i2: %uus)\n",
> -		 active_percent, active_us, inactive_us);
>  	return 0;
>  }
>  
> @@ -465,15 +466,16 @@ int ivpu_pm_dct_disable(struct ivpu_device *vdev)
>  {
>  	int ret;
>  
> +	vdev->pm->dct_active_percent = 0;
> +
> +	ivpu_dbg(vdev, PM, "DCT requested to be disabled\n");
> +
>  	ret = ivpu_jsm_dct_disable(vdev);
>  	if (ret) {
>  		ivpu_err_ratelimited(vdev, "Failed to disable DCT: %d\n", ret);
>  		return ret;
>  	}
>  
> -	vdev->pm->dct_active_percent = 0;
> -
> -	ivpu_dbg(vdev, PM, "DCT disabled\n");
>  	return 0;
>  }
>  
> @@ -486,7 +488,7 @@ void ivpu_pm_irq_dct_work_fn(struct work_struct *work)
>  	if (ivpu_hw_btrs_dct_get_request(vdev, &enable))
>  		return;
>  
> -	if (vdev->pm->dct_active_percent)
> +	if (enable)
>  		ret = ivpu_pm_dct_enable(vdev, DCT_DEFAULT_ACTIVE_PERCENT);
>  	else
>  		ret = ivpu_pm_dct_disable(vdev);