Re: [PATCH 04/20] drm/i915/icl: Enable DSI IO power

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

On Mon, 02 Jul 2018, "Chauhan, Madhav" <madhav.chauhan@intel.com> wrote:
>> -----Original Message-----
>> From: Nikula, Jani
>> Sent: Monday, July 2, 2018 3:27 PM
>> To: Chauhan, Madhav <madhav.chauhan@intel.com>; intel-
>> gfx@lists.freedesktop.org
>> Cc: Zanoni, Paulo R <paulo.r.zanoni@intel.com>; Shankar, Uma
>> <uma.shankar@intel.com>; Vivi, Rodrigo <rodrigo.vivi@intel.com>;
>> Chauhan, Madhav <madhav.chauhan@intel.com>
>> Subject: Re: [PATCH 04/20] drm/i915/icl: Enable DSI IO power
>> 
>> On Fri, 15 Jun 2018, Madhav Chauhan <madhav.chauhan@intel.com> wrote:
>> > This patch configures mode of operation for DSI and enable DDI IO
>> > power by configuring power well.
>> >
>> > Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
>> > ---
>> >  drivers/gpu/drm/i915/intel_dsi_new.c | 22 ++++++++++++++++++++++
>> >  1 file changed, 22 insertions(+)
>> >
>> > diff --git a/drivers/gpu/drm/i915/intel_dsi_new.c
>> > b/drivers/gpu/drm/i915/intel_dsi_new.c
>> > index 0d325ca..5ec4016 100644
>> > --- a/drivers/gpu/drm/i915/intel_dsi_new.c
>> > +++ b/drivers/gpu/drm/i915/intel_dsi_new.c
>> > @@ -55,11 +55,33 @@ static void gen11_dsi_program_esc_clk_div(struct
>> intel_encoder *encoder)
>> >  	}
>> >  }
>> >
>> > +static void gen11_dsi_enable_io_power(struct intel_encoder *encoder)
>> > +{
>> > +	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
>> > +	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
>> > +	enum port port;
>> > +	u32 tmp;
>> > +
>> > +	for_each_dsi_port(port, intel_dsi->ports) {
>> > +		tmp = I915_READ(ICL_DSI_IO_MODECTL(port));
>> > +		tmp |= COMBO_PHY_MODE_DSI;
>> > +		I915_WRITE(ICL_DSI_IO_MODECTL(port), tmp);
>> > +	}
>> > +
>> > +	intel_display_power_get(dev_priv,
>> POWER_DOMAIN_PORT_DDI_A_IO);
>> > +
>> > +	if (intel_dsi->dual_link)
>> > +		intel_display_power_get(dev_priv,
>> POWER_DOMAIN_PORT_DDI_B_IO);
>> 
>> Per bspec, "DSI0 uses DDI A; DSI1 uses DDI B" so shouldn't this be a
>> for_each_dsi_port() too, with the appropriate mapping to power domain?
>
> Do you mean something like this:
>
> enum intel_display_power_domain power_domain;
> for_each_dsi_port()
> {
> 	if (port ==PORT_A)
> 		power_domain = POWER_DOMAIN_PORT_DDI_A_IO;
> 	else if( port == PORT_B)
> 		power_domain = POWER_DOMAIN_PORT_DDI_A_IO;
> 	
> 	intel_display_power_get(dev_priv, power_domain);
> }

That's my understanding of the spec, yes. Maybe simply:

	for_each_dsi_port() {
        	intel_display_power_get(port == PORT_A ?
					POWER_DOMAIN_PORT_DDI_A_IO :
                                        POWER_DOMAIN_PORT_DDI_B_IO)
        }

BR,
Jani.


>
>> 
>> > +}
>> > +
>> >  static void __attribute__((unused)) gen11_dsi_pre_enable(
>> >  				struct intel_encoder *encoder,
>> >  				const struct intel_crtc_state *pipe_config,
>> >  				const struct drm_connector_state
>> *conn_state)
>> 
>> Please don't end lines in (. You can add a newline before the function
>> name:
>> 
>> static void __attribute__((unused))
>> gen11_dsi_pre_enable(struct intel_encoder *encoder,
>> 		     const struct intel_crtc_state *pipe_config,
>> 		     const struct drm_connector_state *conn_state)
>> 
>
> Got it. Thanks!!
>
> Regards,
> Madhav
>
>> >  {
>> > +	/* step2: enable IO power */
>> > +	gen11_dsi_enable_io_power(encoder);
>> > +
>> >  	/* step3: enable DSI PLL */
>> >  	gen11_dsi_program_esc_clk_div(encoder);
>> >  }
>> 
>> --
>> Jani Nikula, Intel Open Source Graphics Center

-- 
Jani Nikula, Intel Open Source Graphics Center
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