Chris Wilson <[email protected]> writes:

> This reverts commit 0b702dca26580e3bbfbbaf22dfc29280b6263414.
>
> CI reports that this is not as reliable as it first appears, with
> failures starting to sporadically occur in selftests.
>
> Fixes: 0b702dca2658 ("drm/i915: Avoid waking the engines just to check if 
> they are idle")
> Signed-off-by: Chris Wilson <[email protected]>
> Cc: Mika Kuoppala <[email protected]>
> Cc: Jani Nikula <[email protected]>
> Cc: Joonas Lahtinen <[email protected]>

Reviewed-by: Mika Kuoppala <[email protected]>

> ---
>  drivers/gpu/drm/i915/intel_engine_cs.c | 17 ++++++-----------
>  1 file changed, 6 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c 
> b/drivers/gpu/drm/i915/intel_engine_cs.c
> index 4f244019560d..b7b626195eda 100644
> --- a/drivers/gpu/drm/i915/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/intel_engine_cs.c
> @@ -968,7 +968,6 @@ static bool ring_is_idle(struct intel_engine_cs *engine)
>  {
>       struct drm_i915_private *dev_priv = engine->i915;
>       intel_wakeref_t wakeref;
> -     unsigned long flags;
>       bool idle = true;
>  
>       if (I915_SELFTEST_ONLY(!engine->mmio_base))
> @@ -979,19 +978,15 @@ static bool ring_is_idle(struct intel_engine_cs *engine)
>       if (!wakeref)
>               return true;
>  
> -     spin_lock_irqsave(&dev_priv->uncore.lock, flags);
> +     /* First check that no commands are left in the ring */
> +     if ((I915_READ_HEAD(engine) & HEAD_ADDR) !=
> +         (I915_READ_TAIL(engine) & TAIL_ADDR))
> +             idle = false;
>  
> -     /*
> -      * Check that no commands are left in the ring.
> -      *
> -      * If the engine is not awake, both reads return 0 as we do so without
> -      * forcewake.
> -      */
> -     if ((I915_READ_FW(RING_HEAD(engine->mmio_base)) & HEAD_ADDR) !=
> -         (I915_READ_FW(RING_TAIL(engine->mmio_base)) & TAIL_ADDR))
> +     /* No bit for gen2, so assume the CS parser is idle */
> +     if (INTEL_GEN(dev_priv) > 2 && !(I915_READ_MODE(engine) & MODE_IDLE))
>               idle = false;
>  
> -     spin_unlock_irqrestore(&dev_priv->uncore.lock, flags);
>       intel_runtime_pm_put(dev_priv, wakeref);
>  
>       return idle;
> -- 
> 2.20.1
>
> _______________________________________________
> Intel-gfx mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
_______________________________________________
Intel-gfx mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to