Re: [PATCH v2 8/8] drm/i915/reset: add modeset_stuck callback to intel_display_reset_prepare()

[Matt Roper]

On Tue, Feb 25, 2025 at 01:14:22PM +0200, Jani Nikula wrote:
> Drop the dependency on gt by providing a callback for trying to unbreak
> stuck modeset. Do intel_gt_set_wedged() via the callback.
> 
> It's by no means pretty, but this is perhaps the most straightforward
> alternative.
> 
> Cc: Matt Roper <matthew.d.ro...@intel.com>
> Signed-off-by: Jani Nikula <jani.nik...@intel.com>

Reviewed-by: Matt Roper <matthew.d.ro...@intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_display_reset.c | 6 +++---
>  drivers/gpu/drm/i915/display/intel_display_reset.h | 5 ++++-
>  drivers/gpu/drm/i915/gt/intel_reset.c              | 7 ++++++-
>  3 files changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_reset.c 
> b/drivers/gpu/drm/i915/display/intel_display_reset.c
> index aafee2df6501..8ef86c896158 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_reset.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_reset.c
> @@ -19,9 +19,9 @@ bool intel_display_reset_test(struct intel_display *display)
>       return display->params.force_reset_modeset_test;
>  }
>  
> -void intel_display_reset_prepare(struct intel_display *display)
> +void intel_display_reset_prepare(struct intel_display *display,
> +                              modeset_stuck_fn modeset_stuck, void *context)
>  {
> -     struct drm_i915_private *dev_priv = to_i915(display->drm);
>       struct drm_modeset_acquire_ctx *ctx = &display->restore.reset_ctx;
>       struct drm_atomic_state *state;
>       int ret;
> @@ -32,7 +32,7 @@ void intel_display_reset_prepare(struct intel_display 
> *display)
>       if (atomic_read(&display->restore.pending_fb_pin)) {
>               drm_dbg_kms(display->drm,
>                           "Modeset potentially stuck, unbreaking through 
> wedging\n");
> -             intel_gt_set_wedged(to_gt(dev_priv));
> +             modeset_stuck(context);
>       }
>  
>       /*
> diff --git a/drivers/gpu/drm/i915/display/intel_display_reset.h 
> b/drivers/gpu/drm/i915/display/intel_display_reset.h
> index 985766cde001..053c3e90ac77 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_reset.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_reset.h
> @@ -10,8 +10,11 @@
>  
>  struct intel_display;
>  
> +typedef void modeset_stuck_fn(void *context);
> +
>  bool intel_display_reset_test(struct intel_display *display);
> -void intel_display_reset_prepare(struct intel_display *display);
> +void intel_display_reset_prepare(struct intel_display *display,
> +                              modeset_stuck_fn modeset_stuck, void *context);
>  void intel_display_reset_finish(struct intel_display *display, bool 
> test_only);
>  
>  #endif /* __INTEL_RESET_H__ */
> diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c 
> b/drivers/gpu/drm/i915/gt/intel_reset.c
> index 2ca12bbf168f..84a8ca167a4e 100644
> --- a/drivers/gpu/drm/i915/gt/intel_reset.c
> +++ b/drivers/gpu/drm/i915/gt/intel_reset.c
> @@ -1405,6 +1405,11 @@ static bool gt_reset_clobbers_display(struct intel_gt 
> *gt)
>       return intel_gt_gpu_reset_clobbers_display(gt) && 
> intel_has_gpu_reset(gt);
>  }
>  
> +static void display_reset_modeset_stuck(void *gt)
> +{
> +     intel_gt_set_wedged(gt);
> +}
> +
>  static void display_reset_prepare(struct intel_gt *gt)
>  {
>       struct drm_i915_private *i915 = gt->i915;
> @@ -1419,7 +1424,7 @@ static void display_reset_prepare(struct intel_gt *gt)
>       smp_mb__after_atomic();
>       wake_up_bit(&gt->reset.flags, I915_RESET_MODESET);
>  
> -     intel_display_reset_prepare(display);
> +     intel_display_reset_prepare(display, display_reset_modeset_stuck, gt);
>  }
>  
>  static void display_reset_finish(struct intel_gt *gt)
> -- 
> 2.39.5
> 

-- 
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation