Re: [PATCH 05/14] drm/i915/dpio: Remove pointless variables from vlv/chv DPLL code

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

On Mon, 22 Apr 2024, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Drop all the local variables for the DPLL dividers for vlv/chv
> and just consult the state directly.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

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

> ---
>  drivers/gpu/drm/i915/display/intel_dpll.c | 62 ++++++++++-------------
>  1 file changed, 27 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dpll.c b/drivers/gpu/drm/i915/display/intel_dpll.c
> index b95032651da0..01f800b6b30e 100644
> --- a/drivers/gpu/drm/i915/display/intel_dpll.c
> +++ b/drivers/gpu/drm/i915/display/intel_dpll.c
> @@ -1899,20 +1899,13 @@ static void vlv_prepare_pll(const struct intel_crtc_state *crtc_state)
>  {
>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>  	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> +	const struct dpll *clock = &crtc_state->dpll;
>  	enum dpio_phy phy = vlv_pipe_to_phy(crtc->pipe);
>  	enum pipe pipe = crtc->pipe;
> -	u32 mdiv;
> -	u32 bestn, bestm1, bestm2, bestp1, bestp2;
> -	u32 coreclk, reg_val;
> +	u32 mdiv, coreclk, reg_val;
>  
>  	vlv_dpio_get(dev_priv);
>  
> -	bestn = crtc_state->dpll.n;
> -	bestm1 = crtc_state->dpll.m1;
> -	bestm2 = crtc_state->dpll.m2;
> -	bestp1 = crtc_state->dpll.p1;
> -	bestp2 = crtc_state->dpll.p2;
> -
>  	/* See eDP HDMI DPIO driver vbios notes doc */
>  
>  	/* PLL B needs special handling */
> @@ -1931,10 +1924,12 @@ static void vlv_prepare_pll(const struct intel_crtc_state *crtc_state)
>  	vlv_dpio_write(dev_priv, phy, VLV_CMN_DW0, 0x610);
>  
>  	/* Set idtafcrecal before PLL is enabled */
> -	mdiv = ((bestm1 << DPIO_M1DIV_SHIFT) | (bestm2 & DPIO_M2DIV_MASK));
> -	mdiv |= ((bestp1 << DPIO_P1_SHIFT) | (bestp2 << DPIO_P2_SHIFT));
> -	mdiv |= ((bestn << DPIO_N_SHIFT));
> -	mdiv |= (1 << DPIO_K_SHIFT);
> +	mdiv = (clock->m1 << DPIO_M1DIV_SHIFT) |
> +		(clock->m2 & DPIO_M2DIV_MASK) |
> +		(clock->p1 << DPIO_P1_SHIFT) |
> +		(clock->p2 << DPIO_P2_SHIFT) |
> +		(clock->n << DPIO_N_SHIFT) |
> +		(1 << DPIO_K_SHIFT);
>  
>  	/*
>  	 * Post divider depends on pixel clock rate, DAC vs digital (and LVDS,
> @@ -2030,19 +2025,14 @@ static void chv_prepare_pll(const struct intel_crtc_state *crtc_state)
>  {
>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>  	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> +	const struct dpll *clock = &crtc_state->dpll;
>  	enum pipe pipe = crtc->pipe;
>  	enum dpio_channel port = vlv_pipe_to_channel(pipe);
>  	enum dpio_phy phy = vlv_pipe_to_phy(crtc->pipe);
> -	u32 loopfilter, tribuf_calcntr;
> -	u32 bestm2, bestp1, bestp2, bestm2_frac;
> -	u32 dpio_val;
> -	int vco;
> +	u32 dpio_val, loopfilter, tribuf_calcntr;
> +	u32 m2_frac;
>  
> -	bestm2_frac = crtc_state->dpll.m2 & 0x3fffff;
> -	bestm2 = crtc_state->dpll.m2 >> 22;
> -	bestp1 = crtc_state->dpll.p1;
> -	bestp2 = crtc_state->dpll.p2;
> -	vco = crtc_state->dpll.vco;
> +	m2_frac = clock->m2 & 0x3fffff;
>  	dpio_val = 0;
>  	loopfilter = 0;
>  
> @@ -2050,27 +2040,29 @@ static void chv_prepare_pll(const struct intel_crtc_state *crtc_state)
>  
>  	/* p1 and p2 divider */
>  	vlv_dpio_write(dev_priv, phy, CHV_CMN_DW13(port),
> -			5 << DPIO_CHV_S1_DIV_SHIFT |
> -			bestp1 << DPIO_CHV_P1_DIV_SHIFT |
> -			bestp2 << DPIO_CHV_P2_DIV_SHIFT |
> -			1 << DPIO_CHV_K_DIV_SHIFT);
> +		       5 << DPIO_CHV_S1_DIV_SHIFT |
> +		       clock->p1 << DPIO_CHV_P1_DIV_SHIFT |
> +		       clock->p2 << DPIO_CHV_P2_DIV_SHIFT |
> +		       1 << DPIO_CHV_K_DIV_SHIFT);
>  
>  	/* Feedback post-divider - m2 */
> -	vlv_dpio_write(dev_priv, phy, CHV_PLL_DW0(port), bestm2);
> +	vlv_dpio_write(dev_priv, phy, CHV_PLL_DW0(port),
> +		       clock->m2 >> 22);
>  
>  	/* Feedback refclk divider - n and m1 */
>  	vlv_dpio_write(dev_priv, phy, CHV_PLL_DW1(port),
> -			DPIO_CHV_M1_DIV_BY_2 |
> -			1 << DPIO_CHV_N_DIV_SHIFT);
> +		       DPIO_CHV_M1_DIV_BY_2 |
> +		       1 << DPIO_CHV_N_DIV_SHIFT);
>  
>  	/* M2 fraction division */
> -	vlv_dpio_write(dev_priv, phy, CHV_PLL_DW2(port), bestm2_frac);
> +	vlv_dpio_write(dev_priv, phy, CHV_PLL_DW2(port),
> +		       m2_frac);
>  
>  	/* M2 fraction division enable */
>  	dpio_val = vlv_dpio_read(dev_priv, phy, CHV_PLL_DW3(port));
>  	dpio_val &= ~(DPIO_CHV_FEEDFWD_GAIN_MASK | DPIO_CHV_FRAC_DIV_EN);
>  	dpio_val |= (2 << DPIO_CHV_FEEDFWD_GAIN_SHIFT);
> -	if (bestm2_frac)
> +	if (m2_frac)
>  		dpio_val |= DPIO_CHV_FRAC_DIV_EN;
>  	vlv_dpio_write(dev_priv, phy, CHV_PLL_DW3(port), dpio_val);
>  
> @@ -2079,22 +2071,22 @@ static void chv_prepare_pll(const struct intel_crtc_state *crtc_state)
>  	dpio_val &= ~(DPIO_CHV_INT_LOCK_THRESHOLD_MASK |
>  					DPIO_CHV_INT_LOCK_THRESHOLD_SEL_COARSE);
>  	dpio_val |= (0x5 << DPIO_CHV_INT_LOCK_THRESHOLD_SHIFT);
> -	if (!bestm2_frac)
> +	if (!m2_frac)
>  		dpio_val |= DPIO_CHV_INT_LOCK_THRESHOLD_SEL_COARSE;
>  	vlv_dpio_write(dev_priv, phy, CHV_PLL_DW9(port), dpio_val);
>  
>  	/* Loop filter */
> -	if (vco == 5400000) {
> +	if (clock->vco == 5400000) {
>  		loopfilter |= (0x3 << DPIO_CHV_PROP_COEFF_SHIFT);
>  		loopfilter |= (0x8 << DPIO_CHV_INT_COEFF_SHIFT);
>  		loopfilter |= (0x1 << DPIO_CHV_GAIN_CTRL_SHIFT);
>  		tribuf_calcntr = 0x9;
> -	} else if (vco <= 6200000) {
> +	} else if (clock->vco <= 6200000) {
>  		loopfilter |= (0x5 << DPIO_CHV_PROP_COEFF_SHIFT);
>  		loopfilter |= (0xB << DPIO_CHV_INT_COEFF_SHIFT);
>  		loopfilter |= (0x3 << DPIO_CHV_GAIN_CTRL_SHIFT);
>  		tribuf_calcntr = 0x9;
> -	} else if (vco <= 6480000) {
> +	} else if (clock->vco <= 6480000) {
>  		loopfilter |= (0x4 << DPIO_CHV_PROP_COEFF_SHIFT);
>  		loopfilter |= (0x9 << DPIO_CHV_INT_COEFF_SHIFT);
>  		loopfilter |= (0x3 << DPIO_CHV_GAIN_CTRL_SHIFT);

-- 
Jani Nikula, Intel