[PATCH 6/7] drm/xe: Stop checking for power_lost on D3Cold

[Nilawar, Badal]

On 10-05-2024 00:46, Rodrigo Vivi wrote:
> GuC reset status is not reliable for this purpose and it is
> once in a while ending up in a situation of D3Cold, where
> power_reset is false and without the proper memory restoration
> the GuC reload and Display will fail to come back from D3Cold.
> 
> So, let's do a full restoration of everything if we have a risk
> of losing power, without further optimizations.
> 
> v2: also remove the gut_in_reset function (Anshuman)
> 
> Cc: Anshuman Gupta <anshuman.gupta at intel.com>
> Reviewed-by: Anshuman Gupta <anshuman.gupta at intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> ---
>   drivers/gpu/drm/xe/xe_device_types.h |  3 ---
>   drivers/gpu/drm/xe/xe_guc.c          | 27 ---------------------------
>   drivers/gpu/drm/xe/xe_guc.h          |  1 -
>   drivers/gpu/drm/xe/xe_pm.c           | 12 ++----------
>   4 files changed, 2 insertions(+), 41 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index 906b98fb973b..471c848b2638 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -431,9 +431,6 @@ struct xe_device {
>   		/** @d3cold.allowed: Indicates if d3cold is a valid device state */
>   		bool allowed;
>   
> -		/** @d3cold.power_lost: Indicates if card has really lost power. */
> -		bool power_lost;
> -
>   		/**
>   		 * @d3cold.vram_threshold:
>   		 *
> diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
> index 0c9938e0ab8c..7860b720a99c 100644
> --- a/drivers/gpu/drm/xe/xe_guc.c
> +++ b/drivers/gpu/drm/xe/xe_guc.c
> @@ -938,30 +938,3 @@ void xe_guc_print_info(struct xe_guc *guc, struct drm_printer *p)
>   	xe_guc_ct_print(&guc->ct, p, false);
>   	xe_guc_submit_print(guc, p);
>   }
> -
> -/**
> - * xe_guc_in_reset() - Detect if GuC MIA is in reset.
> - * @guc: The GuC object
> - *
> - * This function detects runtime resume from d3cold by leveraging
> - * GUC_STATUS, GUC doesn't get reset during d3hot,
> - * it strictly to be called from RPM resume handler.
> - *
> - * Return: true if failed to get forcewake or GuC MIA is in Reset,
> - * otherwise false.
> - */
> -bool xe_guc_in_reset(struct xe_guc *guc)
> -{
> -	struct xe_gt *gt = guc_to_gt(guc);
> -	u32 status;
> -	int err;
> -
> -	err = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
> -	if (err)
> -		return true;
> -
> -	status = xe_mmio_read32(gt, GUC_STATUS);
> -	xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
> -
> -	return  status & GS_MIA_IN_RESET;
> -}
> diff --git a/drivers/gpu/drm/xe/xe_guc.h b/drivers/gpu/drm/xe/xe_guc.h
> index a3c92b74a3d5..af59c9545753 100644
> --- a/drivers/gpu/drm/xe/xe_guc.h
> +++ b/drivers/gpu/drm/xe/xe_guc.h
> @@ -37,7 +37,6 @@ void xe_guc_reset_wait(struct xe_guc *guc);
>   void xe_guc_stop_prepare(struct xe_guc *guc);
>   void xe_guc_stop(struct xe_guc *guc);
>   int xe_guc_start(struct xe_guc *guc);
> -bool xe_guc_in_reset(struct xe_guc *guc);
>   
>   static inline u16 xe_engine_class_to_guc_class(enum xe_engine_class class)
>   {
> diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
> index a2f5a1b11cbf..de3b5df65e48 100644
> --- a/drivers/gpu/drm/xe/xe_pm.c
> +++ b/drivers/gpu/drm/xe/xe_pm.c
> @@ -404,15 +404,7 @@ int xe_pm_runtime_resume(struct xe_device *xe)
>   
>   	lock_map_acquire(&xe_pm_runtime_lockdep_map);
>   
> -	/*
> -	 * It can be possible that xe has allowed d3cold but other pcie devices
> -	 * in gfx card soc would have blocked d3cold, therefore card has not
> -	 * really lost power. Detecting primary Gt power is sufficient.
> -	 */
> -	gt = xe_device_get_gt(xe, 0);
> -	xe->d3cold.power_lost = xe_guc_in_reset(&gt->uc.guc);
> -
> -	if (xe->d3cold.allowed && xe->d3cold.power_lost) {
> +	if (xe->d3cold.allowed) {
>   		err = xe_pcode_ready(xe, true);
>   		if (err)
>   			goto out;
> @@ -433,7 +425,7 @@ int xe_pm_runtime_resume(struct xe_device *xe)
>   	for_each_gt(gt, xe, id)
>   		xe_gt_resume(gt);
>   
> -	if (xe->d3cold.allowed && xe->d3cold.power_lost) {
> +	if (xe->d3cold.allowed) {
Reviewed-by: Badal Nilawar <badal.nilawar at intel.com>
>   		xe_display_pm_resume(xe, true);
>   		err = xe_bo_restore_user(xe);
>   		if (err)