drm/i915/hsw: Use the read-out WRPLL/SPLL state instead of reading out again

Instead of reading out the WRPLL/SPLL control values from HW, we can use
the DPLL state that was already read out, or swapped-to.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200226203455.23032-13-imre.deak@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
index b87b4ff..7e6da58 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
+++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
@@ -880,13 +880,10 @@ hsw_ddi_wrpll_get_dpll(struct intel_atomic_state *state,
 static int hsw_ddi_wrpll_get_freq(struct drm_i915_private *dev_priv,
                                  const struct intel_shared_dpll *pll)
 {
-       i915_reg_t reg = pll->info->id == DPLL_ID_WRPLL1 ?
-                                         WRPLL_CTL(0) : WRPLL_CTL(1);
        int refclk;
        int n, p, r;
-       u32 wrpll;
+       u32 wrpll = pll->state.hw_state.wrpll;
 
-       wrpll = intel_de_read(dev_priv, reg);
        switch (wrpll & WRPLL_REF_MASK) {
        case WRPLL_REF_SPECIAL_HSW:
                /*
@@ -1003,7 +1000,7 @@ static int hsw_ddi_spll_get_freq(struct drm_i915_private *i915,
 {
        int link_clock = 0;
 
-       switch (intel_de_read(i915, SPLL_CTL) & SPLL_FREQ_MASK) {
+       switch (pll->state.hw_state.spll & SPLL_FREQ_MASK) {
        case SPLL_FREQ_810MHz:
                link_clock = 81000;
                break;