Re: [PATCH v5 11/12] drm/xe/pm/s2idle: Don't evict user BOs for D3hot and D3cold-VRSR state

[Matthew Auld <matthew.auld@intel.com>]

On 15/10/2025 09:07, Badal Nilawar wrote:
> In D3hot and D3cold-VRSR, VRAM remains active, so it is not necessary
> to evict user BOs.
> 
> Cc: Matthew Auld <matthew.auld@intel.com>
> Co-developed-by: Sk Anirban <sk.anirban@intel.com>
> Signed-off-by: Sk Anirban <sk.anirban@intel.com>
> Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_pm.c | 15 ++++++++++-----
>   1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
> index 84cd9e84f548..51ff9b90fbfd 100644
> --- a/drivers/gpu/drm/xe/xe_pm.c
> +++ b/drivers/gpu/drm/xe/xe_pm.c
> @@ -169,7 +169,7 @@ static void xe_rpm_lockmap_release(const struct xe_device *xe)
>   
>   static void xe_pm_suspend_prepare(struct xe_device *xe)
>   {
> -	if (pm_suspend_target_state == PM_SUSPEND_TO_IDLE)
> +	if (pm_suspend_default_s2idle())
>   		xe_pm_d3cold_target_state_toggle(xe);
>   	else
>   		xe->d3cold.target_state = XE_D3COLD_OFF;
> @@ -191,8 +191,6 @@ int xe_pm_suspend(struct xe_device *xe)
>   	xe_pm_block_begin_signalling();
>   	trace_xe_pm_suspend(xe, __builtin_return_address(0));
>   
> -	xe_pm_suspend_prepare(xe);
> -
>   	err = xe_pxp_pm_suspend(xe->pxp);
>   	if (err)
>   		goto err;
> @@ -543,8 +541,12 @@ static int xe_pm_notifier_callback(struct notifier_block *nb,
>   	int err = 0;
>   
>   	switch (action) {
> -	case PM_HIBERNATION_PREPARE:
>   	case PM_SUSPEND_PREPARE:
> +		xe_pm_suspend_prepare(xe);
> +		if (xe->d3cold.target_state != XE_D3COLD_OFF)
> +			break;

I think this will break hibernation on igpu platforms with flat-CSS? We 
need evict_all() to move CCS from stolen memory back to normal RAM such 
that it is saved and then restored correctly on resume from hibernation. 
What is the value of target_state for a hibernation event? Does the 
evict_all() still get called later? AFAICT it is not called any more.


> +		fallthrough;
> +	case PM_HIBERNATION_PREPARE:
>   	{
>   		struct xe_validation_ctx ctx;
>   
> @@ -569,8 +571,11 @@ static int xe_pm_notifier_callback(struct notifier_block *nb,
>   		xe_pm_block_end_signalling();
>   		break;
>   	}
> -	case PM_POST_HIBERNATION:
>   	case PM_POST_SUSPEND:
> +		if (xe->d3cold.target_state != XE_D3COLD_OFF)
> +			break;
> +		fallthrough;
> +	case PM_POST_HIBERNATION:
>   		complete_all(&xe->pm_block);
>   		xe_pm_wake_rebind_workers(xe);
>   		xe_bo_notifier_unprepare_all_pinned(xe);