Re: [PATCH 4/4] drm/i915: Get rid of the _unchecked() runime pm stuff

[Jani Nikula <jani.nikula@linux.intel.com>]

On Tue, 11 Feb 2025, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Seem to me that intel_runtime_pm.c already handles the
> CONFIG_DRM_I915_DEBUG_RUNTIME_PM=n case perfectly fine
> internally, so I don't understand why it's being leaked into
> all the callers as well. Get rid of all this the externally
> visible _unchecked() stuff.

I think I've sent a similar patch in the past, and I think Imre
explained the rationale was that passing the wakeref around for
non-debug builds increases code size by 1k or something.

Yet this optimization makes the code harder to read.

I'm a bit divided on this one.

Cc: Imre


BR,
Jani.









>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  .../drm/i915/display/intel_display_power.c    | 24 ---------------
>  .../drm/i915/display/intel_display_power.h    | 30 -------------------
>  drivers/gpu/drm/i915/intel_gvt.c              |  3 --
>  drivers/gpu/drm/i915/intel_runtime_pm.c       | 19 ------------
>  drivers/gpu/drm/i915/intel_runtime_pm.h       |  9 ------
>  5 files changed, 85 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
> index d93f43d145a9..20296ab450bf 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> @@ -809,7 +809,6 @@ intel_display_power_flush_work_sync(struct intel_display *display)
>  	drm_WARN_ON(display->drm, power_domains->async_put_wakeref);
>  }
>  
> -#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
>  /**
>   * intel_display_power_put - release a power domain reference
>   * @display: display device instance
> @@ -829,29 +828,6 @@ void intel_display_power_put(struct intel_display *display,
>  	__intel_display_power_put(display, domain);
>  	intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
>  }
> -#else
> -/**
> - * intel_display_power_put_unchecked - release an unchecked power domain reference
> - * @display: display device instance
> - * @domain: power domain to reference
> - *
> - * This function drops the power domain reference obtained by
> - * intel_display_power_get() and might power down the corresponding hardware
> - * block right away if this is the last reference.
> - *
> - * This function is only for the power domain code's internal use to suppress wakeref
> - * tracking when the corresponding debug kconfig option is disabled, should not
> - * be used otherwise.
> - */
> -void intel_display_power_put_unchecked(struct intel_display *display,
> -				       enum intel_display_power_domain domain)
> -{
> -	struct drm_i915_private *dev_priv = to_i915(display->drm);
> -
> -	__intel_display_power_put(display, domain);
> -	intel_runtime_pm_put_unchecked(&dev_priv->runtime_pm);
> -}
> -#endif
>  
>  void
>  intel_display_power_get_in_set(struct intel_display *display,
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.h b/drivers/gpu/drm/i915/display/intel_display_power.h
> index a3a5c1be8bab..52b8a89b96eb 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.h
> @@ -195,7 +195,6 @@ void __intel_display_power_put_async(struct intel_display *display,
>  				     intel_wakeref_t wakeref,
>  				     int delay_ms);
>  void intel_display_power_flush_work(struct intel_display *display);
> -#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
>  void intel_display_power_put(struct intel_display *display,
>  			     enum intel_display_power_domain domain,
>  			     intel_wakeref_t wakeref);
> @@ -215,35 +214,6 @@ intel_display_power_put_async_delay(struct intel_display *display,
>  {
>  	__intel_display_power_put_async(display, domain, wakeref, delay_ms);
>  }
> -#else
> -void intel_display_power_put_unchecked(struct intel_display *display,
> -				       enum intel_display_power_domain domain);
> -
> -static inline void
> -intel_display_power_put(struct intel_display *display,
> -			enum intel_display_power_domain domain,
> -			intel_wakeref_t wakeref)
> -{
> -	intel_display_power_put_unchecked(display, domain);
> -}
> -
> -static inline void
> -intel_display_power_put_async(struct intel_display *display,
> -			      enum intel_display_power_domain domain,
> -			      intel_wakeref_t wakeref)
> -{
> -	__intel_display_power_put_async(display, domain, INTEL_WAKEREF_DEF, -1);
> -}
> -
> -static inline void
> -intel_display_power_put_async_delay(struct intel_display *display,
> -				    enum intel_display_power_domain domain,
> -				    intel_wakeref_t wakeref,
> -				    int delay_ms)
> -{
> -	__intel_display_power_put_async(display, domain, INTEL_WAKEREF_DEF, delay_ms);
> -}
> -#endif
>  
>  void
>  intel_display_power_get_in_set(struct intel_display *display,
> diff --git a/drivers/gpu/drm/i915/intel_gvt.c b/drivers/gpu/drm/i915/intel_gvt.c
> index dae9dce7d1b3..164be5b8acb3 100644
> --- a/drivers/gpu/drm/i915/intel_gvt.c
> +++ b/drivers/gpu/drm/i915/intel_gvt.c
> @@ -310,10 +310,7 @@ EXPORT_SYMBOL_NS_GPL(__intel_context_do_pin, "I915_GVT");
>  EXPORT_SYMBOL_NS_GPL(__intel_context_do_unpin, "I915_GVT");
>  EXPORT_SYMBOL_NS_GPL(intel_ring_begin, "I915_GVT");
>  EXPORT_SYMBOL_NS_GPL(intel_runtime_pm_get, "I915_GVT");
> -#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
>  EXPORT_SYMBOL_NS_GPL(intel_runtime_pm_put, "I915_GVT");
> -#endif
> -EXPORT_SYMBOL_NS_GPL(intel_runtime_pm_put_unchecked, "I915_GVT");
>  EXPORT_SYMBOL_NS_GPL(intel_uncore_forcewake_for_reg, "I915_GVT");
>  EXPORT_SYMBOL_NS_GPL(intel_uncore_forcewake_get, "I915_GVT");
>  EXPORT_SYMBOL_NS_GPL(intel_uncore_forcewake_put, "I915_GVT");
> diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
> index 8d9f4c410546..070bafb0a460 100644
> --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> @@ -322,24 +322,6 @@ intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
>  	__intel_runtime_pm_put(rpm, wref, false);
>  }
>  
> -/**
> - * intel_runtime_pm_put_unchecked - release an unchecked runtime pm reference
> - * @rpm: the intel_runtime_pm structure
> - *
> - * This function drops the device-level runtime pm reference obtained by
> - * intel_runtime_pm_get() and might power down the corresponding
> - * hardware block right away if this is the last reference.
> - *
> - * This function exists only for historical reasons and should be avoided in
> - * new code, as the correctness of its use cannot be checked. Always use
> - * intel_runtime_pm_put() instead.
> - */
> -void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm)
> -{
> -	__intel_runtime_pm_put(rpm, INTEL_WAKEREF_DEF, true);
> -}
> -
> -#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
>  /**
>   * intel_runtime_pm_put - release a runtime pm reference
>   * @rpm: the intel_runtime_pm structure
> @@ -353,7 +335,6 @@ void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
>  {
>  	__intel_runtime_pm_put(rpm, wref, true);
>  }
> -#endif
>  
>  /**
>   * intel_runtime_pm_enable - enable runtime pm
> diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.h b/drivers/gpu/drm/i915/intel_runtime_pm.h
> index 7428bd8fa67f..6eee55e3ff0b 100644
> --- a/drivers/gpu/drm/i915/intel_runtime_pm.h
> +++ b/drivers/gpu/drm/i915/intel_runtime_pm.h
> @@ -204,16 +204,7 @@ intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm);
>  	for ((wf) = intel_runtime_pm_get_if_active(rpm); (wf); \
>  	     intel_runtime_pm_put((rpm), (wf)), (wf) = NULL)
>  
> -void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm);
> -#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
>  void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref);
> -#else
> -static inline void
> -intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
> -{
> -	intel_runtime_pm_put_unchecked(rpm);
> -}
> -#endif
>  void intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref);
>  
>  #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)

-- 
Jani Nikula, Intel