[Intel-gfx] [PATCH v2 2/3] drm/i915: Nuke aux regs from intel_dp

Pandiyan, Dhinakaran dhinakaran.pandiyan at intel.com
Thu Feb 22 20:38:21 UTC 2018




On Thu, 2018-02-22 at 14:43 +0200, Ville Syrjälä wrote:
> On Thu, Feb 22, 2018 at 07:16:07AM +0000, Pandiyan, Dhinakaran wrote:
> > 
> > On Tue, 2018-02-20 at 21:00 +0200, Ville Syrjala wrote:
> > > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > 
> > > Just store function pointers that give us the correct register offsets
> > > instead of storing the register offsets themselves. Slightly less
> > > efficient perhaps but saves a few bytes and better matches how we do
> > > things elsewhere.
> > > 
> > > v2: Keep a local array of data registers (Chris)
> > > 
> > Intriguing, why bother storing register offsets in one go if it's okay
> > to make these additional function calls for every aux transaction.
> > 
> > What am I missing here?
> 
> Slight optimization to do them only once per aux transfer instead of
> potentially multiple times on account of the retry loops.
> 

Yeah, that optimization intrigued me because the additional function
calls this patch introduces make the existing code suboptimal. :)
That's enough bikeshed I suppose, thanks for your answer.


> > 
> > 
> > 
> > > Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
> > > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/intel_dp.c  | 85 ++++++++++++++++++++--------------------
> > >  drivers/gpu/drm/i915/intel_drv.h |  5 ++-
> > >  2 files changed, 45 insertions(+), 45 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > > index eeb8a026fd08..b0c273b5b2a9 100644
> > > --- a/drivers/gpu/drm/i915/intel_dp.c
> > > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > > @@ -936,7 +936,7 @@ static uint32_t
> > >  intel_dp_aux_wait_done(struct intel_dp *intel_dp, bool has_aux_irq)
> > >  {
> > >  	struct drm_i915_private *dev_priv = to_i915(intel_dp_to_dev(intel_dp));
> > > -	i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg;
> > > +	i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp);
> > >  	uint32_t status;
> > >  	bool done;
> > >  
> > > @@ -1089,7 +1089,7 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
> > >  	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
> > >  	struct drm_i915_private *dev_priv =
> > >  			to_i915(intel_dig_port->base.base.dev);
> > > -	i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg;
> > > +	i915_reg_t ch_ctl, ch_data[5];
> > >  	uint32_t aux_clock_divider;
> > >  	int i, ret, recv_bytes;
> > >  	uint32_t status;
> > > @@ -1097,6 +1097,10 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
> > >  	bool has_aux_irq = HAS_AUX_IRQ(dev_priv);
> > >  	bool vdd;
> > >  
> > > +	ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp);
> > > +	for (i = 0; i < ARRAY_SIZE(ch_data); i++)
> > > +		     ch_data[i] = intel_dp->aux_ch_data_reg(intel_dp, i);
> > > +
> > >  	pps_lock(intel_dp);
> > >  
> > >  	/*
> > > @@ -1154,7 +1158,7 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
> > >  		for (try = 0; try < 5; try++) {
> > >  			/* Load the send data into the aux channel data registers */
> > >  			for (i = 0; i < send_bytes; i += 4)
> > > -				I915_WRITE(intel_dp->aux_ch_data_reg[i >> 2],
> > > +				I915_WRITE(ch_data[i >> 2],
> > >  					   intel_dp_pack_aux(send + i,
> > >  							     send_bytes - i));
> > >  
> > > @@ -1239,7 +1243,7 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
> > >  		recv_bytes = recv_size;
> > >  
> > >  	for (i = 0; i < recv_bytes; i += 4)
> > > -		intel_dp_unpack_aux(I915_READ(intel_dp->aux_ch_data_reg[i >> 2]),
> > > +		intel_dp_unpack_aux(I915_READ(ch_data[i >> 2]),
> > >  				    recv + i, recv_bytes - i);
> > >  
> > >  	ret = recv_bytes;
> > > @@ -1396,9 +1400,11 @@ intel_aux_power_domain(struct intel_dp *intel_dp)
> > >  	}
> > >  }
> > >  
> > > -static i915_reg_t g4x_aux_ctl_reg(struct drm_i915_private *dev_priv,
> > > -				  enum aux_ch aux_ch)
> > > +static i915_reg_t g4x_aux_ctl_reg(struct intel_dp *intel_dp)
> > >  {
> > > +	struct drm_i915_private *dev_priv = to_i915(intel_dp_to_dev(intel_dp));
> > > +	enum aux_ch aux_ch = intel_dp->aux_ch;
> > > +
> > >  	switch (aux_ch) {
> > >  	case AUX_CH_B:
> > >  	case AUX_CH_C:
> > > @@ -1410,9 +1416,11 @@ static i915_reg_t g4x_aux_ctl_reg(struct drm_i915_private *dev_priv,
> > >  	}
> > >  }
> > >  
> > > -static i915_reg_t g4x_aux_data_reg(struct drm_i915_private *dev_priv,
> > > -				   enum aux_ch aux_ch, int index)
> > > +static i915_reg_t g4x_aux_data_reg(struct intel_dp *intel_dp, int index)
> > >  {
> > > +	struct drm_i915_private *dev_priv = to_i915(intel_dp_to_dev(intel_dp));
> > > +	enum aux_ch aux_ch = intel_dp->aux_ch;
> > > +
> > >  	switch (aux_ch) {
> > >  	case AUX_CH_B:
> > >  	case AUX_CH_C:
> > > @@ -1424,9 +1432,11 @@ static i915_reg_t g4x_aux_data_reg(struct drm_i915_private *dev_priv,
> > >  	}
> > >  }
> > >  
> > > -static i915_reg_t ilk_aux_ctl_reg(struct drm_i915_private *dev_priv,
> > > -				  enum aux_ch aux_ch)
> > > +static i915_reg_t ilk_aux_ctl_reg(struct intel_dp *intel_dp)
> > >  {
> > > +	struct drm_i915_private *dev_priv = to_i915(intel_dp_to_dev(intel_dp));
> > > +	enum aux_ch aux_ch = intel_dp->aux_ch;
> > > +
> > >  	switch (aux_ch) {
> > >  	case AUX_CH_A:
> > >  		return DP_AUX_CH_CTL(aux_ch);
> > > @@ -1440,9 +1450,11 @@ static i915_reg_t ilk_aux_ctl_reg(struct drm_i915_private *dev_priv,
> > >  	}
> > >  }
> > >  
> > > -static i915_reg_t ilk_aux_data_reg(struct drm_i915_private *dev_priv,
> > > -				   enum aux_ch aux_ch, int index)
> > > +static i915_reg_t ilk_aux_data_reg(struct intel_dp *intel_dp, int index)
> > >  {
> > > +	struct drm_i915_private *dev_priv = to_i915(intel_dp_to_dev(intel_dp));
> > > +	enum aux_ch aux_ch = intel_dp->aux_ch;
> > > +
> > >  	switch (aux_ch) {
> > >  	case AUX_CH_A:
> > >  		return DP_AUX_CH_DATA(aux_ch, index);
> > > @@ -1456,9 +1468,11 @@ static i915_reg_t ilk_aux_data_reg(struct drm_i915_private *dev_priv,
> > >  	}
> > >  }
> > >  
> > > -static i915_reg_t skl_aux_ctl_reg(struct drm_i915_private *dev_priv,
> > > -				  enum aux_ch aux_ch)
> > > +static i915_reg_t skl_aux_ctl_reg(struct intel_dp *intel_dp)
> > >  {
> > > +	struct drm_i915_private *dev_priv = to_i915(intel_dp_to_dev(intel_dp));
> > > +	enum aux_ch aux_ch = intel_dp->aux_ch;
> > > +
> > >  	switch (aux_ch) {
> > >  	case AUX_CH_A:
> > >  	case AUX_CH_B:
> > > @@ -1472,9 +1486,11 @@ static i915_reg_t skl_aux_ctl_reg(struct drm_i915_private *dev_priv,
> > >  	}
> > >  }
> > >  
> > > -static i915_reg_t skl_aux_data_reg(struct drm_i915_private *dev_priv,
> > > -				   enum aux_ch aux_ch, int index)
> > > +static i915_reg_t skl_aux_data_reg(struct intel_dp *intel_dp, int index)
> > >  {
> > > +	struct drm_i915_private *dev_priv = to_i915(intel_dp_to_dev(intel_dp));
> > > +	enum aux_ch aux_ch = intel_dp->aux_ch;
> > > +
> > >  	switch (aux_ch) {
> > >  	case AUX_CH_A:
> > >  	case AUX_CH_B:
> > > @@ -1488,37 +1504,20 @@ static i915_reg_t skl_aux_data_reg(struct drm_i915_private *dev_priv,
> > >  	}
> > >  }
> > >  
> > > -static i915_reg_t intel_aux_ctl_reg(struct drm_i915_private *dev_priv,
> > > -				    enum aux_ch aux_ch)
> > > -{
> > > -	if (INTEL_GEN(dev_priv) >= 9)
> > > -		return skl_aux_ctl_reg(dev_priv, aux_ch);
> > > -	else if (HAS_PCH_SPLIT(dev_priv))
> > > -		return ilk_aux_ctl_reg(dev_priv, aux_ch);
> > > -	else
> > > -		return g4x_aux_ctl_reg(dev_priv, aux_ch);
> > > -}
> > > -
> > > -static i915_reg_t intel_aux_data_reg(struct drm_i915_private *dev_priv,
> > > -				     enum aux_ch aux_ch, int index)
> > > -{
> > > -	if (INTEL_GEN(dev_priv) >= 9)
> > > -		return skl_aux_data_reg(dev_priv, aux_ch, index);
> > > -	else if (HAS_PCH_SPLIT(dev_priv))
> > > -		return ilk_aux_data_reg(dev_priv, aux_ch, index);
> > > -	else
> > > -		return g4x_aux_data_reg(dev_priv, aux_ch, index);
> > > -}
> > > -
> > >  static void intel_aux_reg_init(struct intel_dp *intel_dp)
> > >  {
> > >  	struct drm_i915_private *dev_priv = to_i915(intel_dp_to_dev(intel_dp));
> > > -	enum aux_ch aux_ch = intel_dp->aux_ch;
> > > -	int i;
> > >  
> > > -	intel_dp->aux_ch_ctl_reg = intel_aux_ctl_reg(dev_priv, aux_ch);
> > > -	for (i = 0; i < ARRAY_SIZE(intel_dp->aux_ch_data_reg); i++)
> > > -		intel_dp->aux_ch_data_reg[i] = intel_aux_data_reg(dev_priv, aux_ch, i);
> > > +	if (INTEL_GEN(dev_priv) >= 9) {
> > > +		intel_dp->aux_ch_ctl_reg = skl_aux_ctl_reg;
> > > +		intel_dp->aux_ch_data_reg = skl_aux_data_reg;
> > > +	} else if (HAS_PCH_SPLIT(dev_priv)) {
> > > +		intel_dp->aux_ch_ctl_reg = ilk_aux_ctl_reg;
> > > +		intel_dp->aux_ch_data_reg = ilk_aux_data_reg;
> > > +	} else {
> > > +		intel_dp->aux_ch_ctl_reg = g4x_aux_ctl_reg;
> > > +		intel_dp->aux_ch_data_reg = g4x_aux_data_reg;
> > > +	}
> > >  }
> > >  
> > >  static void
> > > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > > index 7f6a7f592fe6..a72820fe5262 100644
> > > --- a/drivers/gpu/drm/i915/intel_drv.h
> > > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > > @@ -1038,8 +1038,6 @@ struct intel_dp_compliance {
> > >  
> > >  struct intel_dp {
> > >  	i915_reg_t output_reg;
> > > -	i915_reg_t aux_ch_ctl_reg;
> > > -	i915_reg_t aux_ch_data_reg[5];
> > >  	uint32_t DP;
> > >  	int link_rate;
> > >  	uint8_t lane_count;
> > > @@ -1124,6 +1122,9 @@ struct intel_dp {
> > >  				     int send_bytes,
> > >  				     uint32_t aux_clock_divider);
> > >  
> > > +	i915_reg_t (*aux_ch_ctl_reg)(struct intel_dp *dp);
> > > +	i915_reg_t (*aux_ch_data_reg)(struct intel_dp *dp, int index);
> > > +
> > >  	/* This is called before a link training is starterd */
> > >  	void (*prepare_link_retrain)(struct intel_dp *intel_dp);
> > >  
> 


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