On Wed, 29 Jan 2025, Mika Kahola <mika.kah...@intel.com> wrote:
> For PLL programming for C10 and C20 we don't need to
> carry crtc_state but instead use only necessary parts
> of the crtc_state i.e. pll_state.

This is not a good enough justification alone. Usually we pass
crtc_state around because we're going to need more stuff from there
anyway. In that case, someone's going to have to reverse this, or pass a
bunch more parameters than just "is_dp".

I see that you're doing this because you actually need this in a context
that doens't have crtc_state. Then *that* needs to be the rationale.

Even so, there's a good chance this will bite us later.


BR,
Jani.


>
> Signed-off-by: Mika Kahola <mika.kah...@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_cx0_phy.c | 109 +++++++++++--------
>  1 file changed, 64 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c 
> b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> index 48b0b9755b2b..bffe3d4bbe8b 100644
> --- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> +++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> @@ -2021,13 +2021,12 @@ intel_c10pll_tables_get(struct intel_crtc_state 
> *crtc_state,
>       return NULL;
>  }
>  
> -static void intel_cx0pll_update_ssc(struct intel_crtc_state *crtc_state,
> -                                 struct intel_encoder *encoder)
> +static void intel_cx0pll_update_ssc(struct intel_encoder *encoder,
> +                                 struct intel_cx0pll_state *pll_state, bool 
> is_dp)
>  {
>       struct intel_display *display = to_intel_display(encoder);
> -     struct intel_cx0pll_state *pll_state = 
> &crtc_state->dpll_hw_state.cx0pll;
>  
> -     if (intel_crtc_has_dp_encoder(crtc_state)) {
> +     if (is_dp) {
>               if (intel_panel_use_ssc(display)) {
>                       struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
>                       pll_state->ssc_enabled =
> @@ -2036,11 +2035,10 @@ static void intel_cx0pll_update_ssc(struct 
> intel_crtc_state *crtc_state,
>       }
>  }
>  
> -static void intel_c10pll_update_pll(struct intel_crtc_state *crtc_state,
> -                                 struct intel_encoder *encoder)
> +static void intel_c10pll_update_pll(struct intel_encoder *encoder,
> +                                 struct intel_cx0pll_state *pll_state, bool 
> is_dp)
>  {
>       struct intel_display *display = to_intel_display(encoder);
> -     struct intel_cx0pll_state *pll_state = 
> &crtc_state->dpll_hw_state.cx0pll;
>       int i;
>  
>       if (pll_state->ssc_enabled)
> @@ -2051,32 +2049,49 @@ static void intel_c10pll_update_pll(struct 
> intel_crtc_state *crtc_state,
>               pll_state->c10.pll[i] = 0;
>  }
>  
> +static int intel_c10pll_calc_state_from_table(struct intel_encoder *encoder,
> +                                           const struct intel_c10pll_state * 
> const *tables, int port_clock, bool is_dp,
> +                                           struct intel_cx0pll_state 
> *pll_state)
> +{
> +     int i;
> +
> +     for (i = 0; tables[i]; i++) {
> +             if (port_clock == tables[i]->clock) {
> +                     pll_state->c10 = *tables[i];
> +                     intel_cx0pll_update_ssc(encoder, pll_state, is_dp);
> +                     intel_c10pll_update_pll(encoder, pll_state, is_dp);
> +                     pll_state->use_c10 = true;
> +
> +                     return 0;
> +             }
> +     }
> +
> +     return -EINVAL;
> +}
> +
>  static int intel_c10pll_calc_state(struct intel_crtc_state *crtc_state,
>                                  struct intel_encoder *encoder)
>  {
>       const struct intel_c10pll_state * const *tables;
> -     int i;
> +     int val;
>  
>       tables = intel_c10pll_tables_get(crtc_state, encoder);
>       if (!tables)
>               return -EINVAL;
>  
> -     for (i = 0; tables[i]; i++) {
> -             if (crtc_state->port_clock == tables[i]->clock) {
> -                     crtc_state->dpll_hw_state.cx0pll.c10 = *tables[i];
> -                     intel_cx0pll_update_ssc(crtc_state, encoder);
> -                     intel_c10pll_update_pll(crtc_state, encoder);
> -                     crtc_state->dpll_hw_state.cx0pll.use_c10 = true;
> -
> -                     return 0;
> -             }
> -     }
> +     val = intel_c10pll_calc_state_from_table(encoder, tables,
> +                                              crtc_state->port_clock, 
> intel_crtc_has_dp_encoder(crtc_state),
> +                                              
> &crtc_state->dpll_hw_state.cx0pll);
> +     if (val == 0)
> +             return 0;
>  
>       /* For HDMI PLLs try SNPS PHY algorithm, if there are no precomputed 
> tables */
>       if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI)) {
>               
> intel_snps_hdmi_pll_compute_c10pll(&crtc_state->dpll_hw_state.cx0pll.c10,
>                                                  crtc_state->port_clock);
> -             intel_c10pll_update_pll(crtc_state, encoder);
> +             intel_c10pll_update_pll(encoder,
> +                                     &crtc_state->dpll_hw_state.cx0pll,
> +                                     intel_crtc_has_dp_encoder(crtc_state));
>               crtc_state->dpll_hw_state.cx0pll.use_c10 = true;
>  
>               return 0;
> @@ -2112,10 +2127,9 @@ static void intel_c10pll_readout_hw_state(struct 
> intel_encoder *encoder,
>  }
>  
>  static void intel_c10_pll_program(struct intel_display *display,
> -                               const struct intel_crtc_state *crtc_state,
> -                               struct intel_encoder *encoder)
> +                               struct intel_encoder *encoder,
> +                               const struct intel_c10pll_state *pll_state)
>  {
> -     const struct intel_c10pll_state *pll_state = 
> &crtc_state->dpll_hw_state.cx0pll.c10;
>       int i;
>  
>       intel_cx0_rmw(encoder, INTEL_CX0_BOTH_LANES, PHY_C10_VDR_CONTROL(1),
> @@ -2334,7 +2348,9 @@ static int intel_c20pll_calc_state(struct 
> intel_crtc_state *crtc_state,
>       for (i = 0; tables[i]; i++) {
>               if (crtc_state->port_clock == tables[i]->clock) {
>                       crtc_state->dpll_hw_state.cx0pll.c20 = *tables[i];
> -                     intel_cx0pll_update_ssc(crtc_state, encoder);
> +                     intel_cx0pll_update_ssc(encoder,
> +                                             
> &crtc_state->dpll_hw_state.cx0pll,
> +                                             
> intel_crtc_has_dp_encoder(crtc_state));
>                       crtc_state->dpll_hw_state.cx0pll.use_c10 = false;
>                       return 0;
>               }
> @@ -2600,19 +2616,14 @@ static int intel_get_c20_custom_width(u32 clock, bool 
> dp)
>  }
>  
>  static void intel_c20_pll_program(struct intel_display *display,
> -                               const struct intel_crtc_state *crtc_state,
> -                               struct intel_encoder *encoder)
> +                               struct intel_encoder *encoder,
> +                               const struct intel_c20pll_state *pll_state,
> +                               int clock, bool dp)
>  {
> -     const struct intel_c20pll_state *pll_state = 
> &crtc_state->dpll_hw_state.cx0pll.c20;
> -     bool dp = false;
>       u8 owned_lane_mask = intel_cx0_get_owned_lane_mask(encoder);
> -     u32 clock = crtc_state->port_clock;
>       bool cntx;
>       int i;
>  
> -     if (intel_crtc_has_dp_encoder(crtc_state))
> -             dp = true;
> -
>       /* 1. Read current context selection */
>       cntx = intel_cx0_read(encoder, INTEL_CX0_LANE0, 
> PHY_C20_VDR_CUSTOM_SERDES_RATE) & BIT(0);
>  
> @@ -2736,7 +2747,8 @@ static int intel_c10pll_calc_port_clock(struct 
> intel_encoder *encoder,
>  }
>  
>  static void intel_program_port_clock_ctl(struct intel_encoder *encoder,
> -                                      const struct intel_crtc_state 
> *crtc_state,
> +                                      const struct intel_cx0pll_state 
> *pll_state,
> +                                      bool is_dp, int port_clock,
>                                        bool lane_reversal)
>  {
>       struct intel_display *display = to_intel_display(encoder);
> @@ -2751,18 +2763,17 @@ static void intel_program_port_clock_ctl(struct 
> intel_encoder *encoder,
>  
>       val |= XELPDP_FORWARD_CLOCK_UNGATE;
>  
> -     if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI) &&
> -         is_hdmi_frl(crtc_state->port_clock))
> +     if (!is_dp && is_hdmi_frl(port_clock))
>               val |= 
> XELPDP_DDI_CLOCK_SELECT(XELPDP_DDI_CLOCK_SELECT_DIV18CLK);
>       else
>               val |= XELPDP_DDI_CLOCK_SELECT(XELPDP_DDI_CLOCK_SELECT_MAXPCLK);
>  
>       /* TODO: HDMI FRL */
>       /* DP2.0 10G and 20G rates enable MPLLA*/
> -     if (crtc_state->port_clock == 1000000 || crtc_state->port_clock == 
> 2000000)
> -             val |= crtc_state->dpll_hw_state.cx0pll.ssc_enabled ? 
> XELPDP_SSC_ENABLE_PLLA : 0;
> +     if (port_clock == 1000000 || port_clock == 2000000)
> +             val |= pll_state->ssc_enabled ? XELPDP_SSC_ENABLE_PLLA : 0;
>       else
> -             val |= crtc_state->dpll_hw_state.cx0pll.ssc_enabled ? 
> XELPDP_SSC_ENABLE_PLLB : 0;
> +             val |= pll_state->ssc_enabled ? XELPDP_SSC_ENABLE_PLLB : 0;
>  
>       intel_de_rmw(display, XELPDP_PORT_CLOCK_CTL(display, encoder->port),
>                    XELPDP_LANE1_PHY_CLOCK_SELECT | 
> XELPDP_FORWARD_CLOCK_UNGATE |
> @@ -2992,8 +3003,9 @@ static u32 intel_cx0_get_pclk_pll_ack(u8 lane_mask)
>       return val;
>  }
>  
> -static void intel_cx0pll_enable(struct intel_encoder *encoder,
> -                             const struct intel_crtc_state *crtc_state)
> +static void __intel_cx0pll_enable(struct intel_encoder *encoder,
> +                               const struct intel_cx0pll_state *pll_state,
> +                               bool is_dp, int port_clock, int lane_count)
>  {
>       struct intel_display *display = to_intel_display(encoder);
>       enum phy phy = intel_encoder_to_phy(encoder);
> @@ -3007,7 +3019,7 @@ static void intel_cx0pll_enable(struct intel_encoder 
> *encoder,
>        * 1. Program PORT_CLOCK_CTL REGISTER to configure
>        * clock muxes, gating and SSC
>        */
> -     intel_program_port_clock_ctl(encoder, crtc_state, lane_reversal);
> +     intel_program_port_clock_ctl(encoder, pll_state, is_dp, port_clock, 
> lane_reversal);
>  
>       /* 2. Bring PHY out of reset. */
>       intel_cx0_phy_lane_reset(encoder, lane_reversal);
> @@ -3027,15 +3039,15 @@ static void intel_cx0pll_enable(struct intel_encoder 
> *encoder,
>  
>       /* 5. Program PHY internal PLL internal registers. */
>       if (intel_encoder_is_c10phy(encoder))
> -             intel_c10_pll_program(display, crtc_state, encoder);
> +             intel_c10_pll_program(display, encoder, &pll_state->c10);
>       else
> -             intel_c20_pll_program(display, crtc_state, encoder);
> +             intel_c20_pll_program(display, encoder, &pll_state->c20, 
> port_clock, is_dp);
>  
>       /*
>        * 6. Program the enabled and disabled owned PHY lane
>        * transmitters over message bus
>        */
> -     intel_cx0_program_phy_lane(encoder, crtc_state->lane_count, 
> lane_reversal);
> +     intel_cx0_program_phy_lane(encoder, lane_count, lane_reversal);
>  
>       /*
>        * 7. Follow the Display Voltage Frequency Switching - Sequence
> @@ -3046,8 +3058,7 @@ static void intel_cx0pll_enable(struct intel_encoder 
> *encoder,
>        * 8. Program DDI_CLK_VALFREQ to match intended DDI
>        * clock frequency.
>        */
> -     intel_de_write(display, DDI_CLK_VALFREQ(encoder->port),
> -                    crtc_state->port_clock);
> +     intel_de_write(display, DDI_CLK_VALFREQ(encoder->port), port_clock);
>  
>       /*
>        * 9. Set PORT_CLOCK_CTL register PCLK PLL Request
> @@ -3074,6 +3085,14 @@ static void intel_cx0pll_enable(struct intel_encoder 
> *encoder,
>       intel_cx0_phy_transaction_end(encoder, wakeref);
>  }
>  
> +static void intel_cx0pll_enable(struct intel_encoder *encoder,
> +                             const struct intel_crtc_state *crtc_state)
> +{
> +     __intel_cx0pll_enable(encoder, &crtc_state->dpll_hw_state.cx0pll,
> +                           intel_crtc_has_dp_encoder(crtc_state), 
> crtc_state->port_clock, crtc_state->lane_count);
> +
> +}
> +
>  int intel_mtl_tbt_calc_port_clock(struct intel_encoder *encoder)
>  {
>       struct intel_display *display = to_intel_display(encoder);

-- 
Jani Nikula, Intel

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