linux-kernel - Re: [PATCH v4] drm/i915/gen9bc: Handle TGP PCH during suspend/resume

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Message-ID: <20210217211802.GC558393@ideak-desk.fi.intel.com>
Date:   Wed, 17 Feb 2021 23:18:02 +0200
From:   Imre Deak <imre.deak@...el.com>
To:     Lyude Paul <lyude@...hat.com>
Cc:     intel-gfx@...ts.freedesktop.org,
        Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay@...el.com>,
        Matt Roper <matthew.d.roper@...el.com>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        "open list:DRM DRIVERS" <dri-devel@...ts.freedesktop.org>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v4] drm/i915/gen9bc: Handle TGP PCH during suspend/resume

On Wed, Feb 17, 2021 at 01:00:16PM -0500, Lyude Paul wrote:
> From: Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay@...el.com>
> 
> For Legacy S3 suspend/resume GEN9 BC needs to enable and
> setup TGP PCH.
> 
> v2:
> * Move Wa_14010685332 into it's own function - vsyrjala
> * Add TODO comment about figuring out if we can move this workaround - imre
> v3:
> * Rename cnp_irq_post_reset() to cnp_display_clock_wa()
> * Add TODO item mentioning we need to clarify which platforms this
>   workaround applies to
> * Just use ibx_irq_reset() in gen8_irq_reset(). This code should be
>   functionally equivalent on gen9 bc to the code v2 added
> * Drop icp_hpd_irq_setup() call in spt_hpd_irq_setup(), this looks to be
>   more or less identical to spt_hpd_irq_setup() minus additionally enabling
>   one port. Will update i915 to use icp_hpd_irq_setup() for ICP in a
>   separate patch.
> v4:
> * Revert Wa_14010685332 system list in comments to how it was before
> * Add back HAS_PCH_SPLIT() check before calling ibx_irq_reset()
> 
> Cc: Matt Roper <matthew.d.roper@...el.com>
> Signed-off-by: Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay@...el.com>
> Signed-off-by: Lyude Paul <lyude@...hat.com>

Thanks, looks ok to me:
Reviewed-by: Imre Deak <imre.deak@...el.com>

nit: cnp_display_clock_gating_wa() would be an even better name, could
be renamed while applying.

> ---
>  drivers/gpu/drm/i915/i915_irq.c | 49 +++++++++++++++++++++------------
>  1 file changed, 32 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 98145a7f28a4..9b56a8f81e1a 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -3040,6 +3040,24 @@ static void valleyview_irq_reset(struct drm_i915_private *dev_priv)
>  	spin_unlock_irq(&dev_priv->irq_lock);
>  }
>  
> +static void cnp_display_clock_wa(struct drm_i915_private *dev_priv)
> +{
> +	struct intel_uncore *uncore = &dev_priv->uncore;
> +
> +	/*
> +	 * Wa_14010685332:cnp/cmp,tgp,adp
> +	 * TODO: Clarify which platforms this applies to
> +	 * TODO: Figure out if this workaround can be applied in the s0ix suspend/resume handlers as
> +	 * on earlier platforms and whether the workaround is also needed for runtime suspend/resume
> +	 */
> +	if (INTEL_PCH_TYPE(dev_priv) == PCH_CNP ||
> +	    (INTEL_PCH_TYPE(dev_priv) >= PCH_TGP && INTEL_PCH_TYPE(dev_priv) < PCH_DG1)) {
> +		intel_uncore_rmw(uncore, SOUTH_CHICKEN1, SBCLK_RUN_REFCLK_DIS,
> +				 SBCLK_RUN_REFCLK_DIS);
> +		intel_uncore_rmw(uncore, SOUTH_CHICKEN1, SBCLK_RUN_REFCLK_DIS, 0);
> +	}
> +}
> +
>  static void gen8_irq_reset(struct drm_i915_private *dev_priv)
>  {
>  	struct intel_uncore *uncore = &dev_priv->uncore;
> @@ -3063,6 +3081,8 @@ static void gen8_irq_reset(struct drm_i915_private *dev_priv)
>  
>  	if (HAS_PCH_SPLIT(dev_priv))
>  		ibx_irq_reset(dev_priv);
> +
> +	cnp_display_clock_wa(dev_priv);
>  }
>  
>  static void gen11_display_irq_reset(struct drm_i915_private *dev_priv)
> @@ -3104,15 +3124,7 @@ static void gen11_display_irq_reset(struct drm_i915_private *dev_priv)
>  	if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP)
>  		GEN3_IRQ_RESET(uncore, SDE);
>  
> -	/* Wa_14010685332:cnp/cmp,tgp,adp */
> -	if (INTEL_PCH_TYPE(dev_priv) == PCH_CNP ||
> -	    (INTEL_PCH_TYPE(dev_priv) >= PCH_TGP &&
> -	     INTEL_PCH_TYPE(dev_priv) < PCH_DG1)) {
> -		intel_uncore_rmw(uncore, SOUTH_CHICKEN1,
> -				 SBCLK_RUN_REFCLK_DIS, SBCLK_RUN_REFCLK_DIS);
> -		intel_uncore_rmw(uncore, SOUTH_CHICKEN1,
> -				 SBCLK_RUN_REFCLK_DIS, 0);
> -	}
> +	cnp_display_clock_wa(dev_priv);
>  }
>  
>  static void gen11_irq_reset(struct drm_i915_private *dev_priv)
> @@ -3764,9 +3776,19 @@ static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
>  	}
>  }
>  
> +static void icp_irq_postinstall(struct drm_i915_private *dev_priv)
> +{
> +	struct intel_uncore *uncore = &dev_priv->uncore;
> +	u32 mask = SDE_GMBUS_ICP;
> +
> +	GEN3_IRQ_INIT(uncore, SDE, ~mask, 0xffffffff);
> +}
> +
>  static void gen8_irq_postinstall(struct drm_i915_private *dev_priv)
>  {
> -	if (HAS_PCH_SPLIT(dev_priv))
> +	if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP)
> +		icp_irq_postinstall(dev_priv);
> +	else if (HAS_PCH_SPLIT(dev_priv))
>  		ibx_irq_postinstall(dev_priv);
>  
>  	gen8_gt_irq_postinstall(&dev_priv->gt);
> @@ -3775,13 +3797,6 @@ static void gen8_irq_postinstall(struct drm_i915_private *dev_priv)
>  	gen8_master_intr_enable(dev_priv->uncore.regs);
>  }
>  
> -static void icp_irq_postinstall(struct drm_i915_private *dev_priv)
> -{
> -	struct intel_uncore *uncore = &dev_priv->uncore;
> -	u32 mask = SDE_GMBUS_ICP;
> -
> -	GEN3_IRQ_INIT(uncore, SDE, ~mask, 0xffffffff);
> -}
>  
>  static void gen11_irq_postinstall(struct drm_i915_private *dev_priv)
>  {
> -- 
> 2.29.2
>