Re: [PATCH 2/2] drm/i915: move fence timeout to display parent interface

[Maarten Lankhorst <maarten.lankhorst@intel.com>]

Hey,

Den 2026-04-08 kl. 17:21, skrev Jani Nikula:
> i915 has the Kconfig option DRM_I915_FENCE_TIMEOUT, defaulting to 10
> seconds. xe doesn't use it, instead defaulting to MAX_SCHEDULE_TIMEOUT.
>
> There was an attempt to unify the behaviour by switching to
> dma_fence_wait() which defaults to MAX_SCHEDULE_TIMEOUT, but that
> resulted in CI failures. See the link below.
>
> Move the fence timeout to the optional parent interface, retaining
> existing behaviour for each driver. With this, we can drop the xe compat
> i915_config.h header.
>
> While at it, order the declarations in intel_parent.h the same way as in
> the struct.
>
> Link: https://lore.kernel.org/r/20251113155332.789554-1-jani.nikula@intel.com
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Maarten Lankhorst <maarten.lankhorst@intel.com>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c     |  8 ++++++--
>  drivers/gpu/drm/i915/display/intel_parent.c      |  6 ++++++
>  drivers/gpu/drm/i915/display/intel_parent.h      |  3 ++-
>  drivers/gpu/drm/i915/i915_driver.c               |  2 ++
>  .../gpu/drm/xe/compat-i915-headers/i915_config.h | 16 ----------------
>  include/drm/intel/display_parent_interface.h     |  3 +++
>  6 files changed, 19 insertions(+), 19 deletions(-)
>  delete mode 100644 drivers/gpu/drm/xe/compat-i915-headers/i915_config.h
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 58a654ca0d20..765cc09b70da 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -49,7 +49,6 @@
>  #include "g4x_dp.h"
>  #include "g4x_hdmi.h"
>  #include "hsw_ips.h"
> -#include "i915_config.h"
>  #include "i9xx_plane.h"
>  #include "i9xx_plane_regs.h"
>  #include "i9xx_wm.h"
> @@ -105,6 +104,7 @@
>  #include "intel_modeset_verify.h"
>  #include "intel_overlay.h"
>  #include "intel_panel.h"
> +#include "intel_parent.h"
>  #include "intel_pch_display.h"
>  #include "intel_pch_refclk.h"
>  #include "intel_pfit.h"
> @@ -7149,15 +7149,19 @@ static void skl_commit_modeset_enables(struct intel_atomic_state *state)
>  
>  static void intel_atomic_commit_fence_wait(struct intel_atomic_state *intel_state)
>  {
> +	struct intel_display *display = to_intel_display(intel_state);
>  	struct drm_plane *plane;
>  	struct drm_plane_state *new_plane_state;
> +	unsigned long fence_timeout;
>  	long ret;
>  	int i;
>  
> +	fence_timeout = intel_parent_fence_timeout(display);
> +
>  	for_each_new_plane_in_state(&intel_state->base, plane, new_plane_state, i) {
>  		if (new_plane_state->fence) {
>  			ret = dma_fence_wait_timeout(new_plane_state->fence, false,
> -						     i915_fence_timeout());
> +						     fence_timeout);
>  			if (ret <= 0)
>  				break;
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_parent.c b/drivers/gpu/drm/i915/display/intel_parent.c
> index 47ce3b6fdd5b..f22dd16ddb40 100644
> --- a/drivers/gpu/drm/i915/display/intel_parent.c
> +++ b/drivers/gpu/drm/i915/display/intel_parent.c
> @@ -388,6 +388,12 @@ void intel_parent_fence_priority_display(struct intel_display *display, struct d
>  		display->parent->fence_priority_display(fence);
>  }
>  
> +unsigned long intel_parent_fence_timeout(struct intel_display *display)
> +{
> +	return display->parent->fence_timeout ? display->parent->fence_timeout() :
> +		MAX_SCHEDULE_TIMEOUT;
> +}
> +
>  bool intel_parent_has_auxccs(struct intel_display *display)
>  {
>  	return display->parent->has_auxccs && display->parent->has_auxccs(display->drm);
> diff --git a/drivers/gpu/drm/i915/display/intel_parent.h b/drivers/gpu/drm/i915/display/intel_parent.h
> index 1e89d24163cc..f06e0f9f2e41 100644
> --- a/drivers/gpu/drm/i915/display/intel_parent.h
> +++ b/drivers/gpu/drm/i915/display/intel_parent.h
> @@ -120,9 +120,10 @@ int intel_parent_vlv_iosf_write(struct intel_display *display, enum vlv_iosf_sb_
>  int intel_parent_vma_fence_id(struct intel_display *display, const struct i915_vma *vma);
>  
>  /* generic */
> +void intel_parent_fence_priority_display(struct intel_display *display, struct dma_fence *fence);
> +unsigned long intel_parent_fence_timeout(struct intel_display *display);
>  bool intel_parent_has_auxccs(struct intel_display *display);
>  bool intel_parent_has_fenced_regions(struct intel_display *display);
>  bool intel_parent_vgpu_active(struct intel_display *display);
> -void intel_parent_fence_priority_display(struct intel_display *display, struct dma_fence *fence);
>  
>  #endif /* __INTEL_PARENT_H__ */
> diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
> index 129013c5fb42..b7098d80b92d 100644
> --- a/drivers/gpu/drm/i915/i915_driver.c
> +++ b/drivers/gpu/drm/i915/i915_driver.c
> @@ -91,6 +91,7 @@
>  #include "pxp/intel_pxp_pm.h"
>  
>  #include "i915_bo.h"
> +#include "i915_config.h"
>  #include "i915_debugfs.h"
>  #include "i915_display_pc8.h"
>  #include "i915_dpt.h"
> @@ -783,6 +784,7 @@ static const struct intel_display_parent_interface parent = {
>  	.vma = &i915_display_vma_interface,
>  
>  	.fence_priority_display = fence_priority_display,
> +	.fence_timeout = i915_fence_timeout,
>  	.has_auxccs = has_auxccs,
>  	.has_fenced_regions = has_fenced_regions,
>  	.vgpu_active = vgpu_active,
> diff --git a/drivers/gpu/drm/xe/compat-i915-headers/i915_config.h b/drivers/gpu/drm/xe/compat-i915-headers/i915_config.h
> deleted file mode 100644
> index d4522203e2dd..000000000000
> --- a/drivers/gpu/drm/xe/compat-i915-headers/i915_config.h
> +++ /dev/null
> @@ -1,16 +0,0 @@
> -/* SPDX-License-Identifier: MIT */
> -/*
> - * Copyright © 2023 Intel Corporation
> - */
> -
> -#ifndef __I915_CONFIG_H__
> -#define __I915_CONFIG_H__
> -
> -#include <linux/sched.h>
> -
> -static inline unsigned long i915_fence_timeout(void)
> -{
> -	return MAX_SCHEDULE_TIMEOUT;
> -}
> -
> -#endif /* __I915_CONFIG_H__ */
> diff --git a/include/drm/intel/display_parent_interface.h b/include/drm/intel/display_parent_interface.h
> index 258e6388ef77..e0293e6cfdab 100644
> --- a/include/drm/intel/display_parent_interface.h
> +++ b/include/drm/intel/display_parent_interface.h
> @@ -261,6 +261,9 @@ struct intel_display_parent_interface {
>  		/** @fence_priority_display: Set display priority. Optional. */
>  		void (*fence_priority_display)(struct dma_fence *fence);
>  
> +		/** @fence_timeout: Fence timeout. Optional. */
> +		unsigned long (*fence_timeout)(void);
> +
>  		/** @has_auxccs: Are AuxCCS formats supported by the parent. Optional. */
>  		bool (*has_auxccs)(struct drm_device *drm);
>  
I just replied the same but more elaborate in the previous discussion from CI results,
would it be possible to remove waiting for old_obj on gen9+ instead?

Kind regards,
~Maarten Lankhorst