Re: [Intel-gfx] [PATCH 08/10] drm/i915/dvo: Use intel_de_rmw() for DVO enable/disable

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

On Tue, 22 Nov 2022, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Replace the hand rolled RMW with intel_de_rmw() in the DVO
> port enable/disable functions. Also switch to intel_de_posting_read()
> for the posting read (though maybe it should be just be nuked...).
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

I've got an old series adding intel_de_write_post() and
intel_de_rmw_post() that combine the write and the posting read. Wonder
if I should resurrect that. *shrug*.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_dvo.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dvo.c b/drivers/gpu/drm/i915/display/intel_dvo.c
> index a5c464c82e5c..c590a92205f0 100644
> --- a/drivers/gpu/drm/i915/display/intel_dvo.c
> +++ b/drivers/gpu/drm/i915/display/intel_dvo.c
> @@ -185,11 +185,11 @@ static void intel_disable_dvo(struct intel_atomic_state *state,
>  	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
>  	struct intel_dvo *intel_dvo = enc_to_dvo(encoder);
>  	enum port port = encoder->port;
> -	u32 temp = intel_de_read(i915, DVO(port));
>  
>  	intel_dvo->dev.dev_ops->dpms(&intel_dvo->dev, false);
> -	intel_de_write(i915, DVO(port), temp & ~DVO_ENABLE);
> -	intel_de_read(i915, DVO(port));
> +
> +	intel_de_rmw(i915, DVO(port), DVO_ENABLE, 0);
> +	intel_de_posting_read(i915, DVO(port));
>  }
>  
>  static void intel_enable_dvo(struct intel_atomic_state *state,
> @@ -200,14 +200,13 @@ static void intel_enable_dvo(struct intel_atomic_state *state,
>  	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
>  	struct intel_dvo *intel_dvo = enc_to_dvo(encoder);
>  	enum port port = encoder->port;
> -	u32 temp = intel_de_read(i915, DVO(port));
>  
>  	intel_dvo->dev.dev_ops->mode_set(&intel_dvo->dev,
>  					 &pipe_config->hw.mode,
>  					 &pipe_config->hw.adjusted_mode);
>  
> -	intel_de_write(i915, DVO(port), temp | DVO_ENABLE);
> -	intel_de_read(i915, DVO(port));
> +	intel_de_rmw(i915, DVO(port), 0, DVO_ENABLE);
> +	intel_de_posting_read(i915, DVO(port));
>  
>  	intel_dvo->dev.dev_ops->dpms(&intel_dvo->dev, true);
>  }

-- 
Jani Nikula, Intel Open Source Graphics Center