drm/i915: Consider SPLL as another shared pll, v2.

When diagnosing a unrelated bug for someone on irc, it would seem the hardware can
be brought up by the BIOS with the embedded displayport using the SPLL for spread spectrum.

Right now this is not handled well in i915, and it calculates the crtc needs to
be reprogrammed on the first modeset without SSC, but  the SPLL itself was kept
active. Fix this by exposing SPLL as a shared pll that will not be returned
by intel_get_shared_dpll; you have to know it exists to use it.

Changes since v1:
- Create a separate dpll_hw_state.spll for spll, and use
  separate pll functions for spll.

Tested-by: Emil Renner Berthing <kernel@esmil.dk>
Tested-by: Gabriel Feceoru <gabriel.feceoru@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447681332-6318-1-git-send-email-maarten.lankhorst@linux.intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

1 files changed, 4 insertions, 27 deletions

diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index b84aaa0bb48a..6a2c76e367a5 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -138,18 +138,6 @@ static void hsw_crt_get_config(struct intel_encoder *encoder,
 	pipe_config->base.adjusted_mode.flags |= intel_crt_get_flags(encoder);
 }
 
-static void hsw_crt_pre_enable(struct intel_encoder *encoder)
-{
-	struct drm_device *dev = encoder->base.dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
-
-	WARN(I915_READ(SPLL_CTL) & SPLL_PLL_ENABLE, "SPLL already enabled\n");
-	I915_WRITE(SPLL_CTL,
-		   SPLL_PLL_ENABLE | SPLL_PLL_FREQ_1350MHz | SPLL_PLL_SSC);
-	POSTING_READ(SPLL_CTL);
-	udelay(20);
-}
-
 /* Note: The caller is required to filter out dpms modes not supported by the
  * platform. */
 static void intel_crt_set_dpms(struct intel_encoder *encoder, int mode)
@@ -216,19 +204,6 @@ static void pch_post_disable_crt(struct intel_encoder *encoder)
 	intel_disable_crt(encoder);
 }
 
-static void hsw_crt_post_disable(struct intel_encoder *encoder)
-{
-	struct drm_device *dev = encoder->base.dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	uint32_t val;
-
-	DRM_DEBUG_KMS("Disabling SPLL\n");
-	val = I915_READ(SPLL_CTL);
-	WARN_ON(!(val & SPLL_PLL_ENABLE));
-	I915_WRITE(SPLL_CTL, val & ~SPLL_PLL_ENABLE);
-	POSTING_READ(SPLL_CTL);
-}
-
 static void intel_enable_crt(struct intel_encoder *encoder)
 {
 	struct intel_crt *crt = intel_encoder_to_crt(encoder);
@@ -280,6 +255,10 @@ static bool intel_crt_compute_config(struct intel_encoder *encoder,
 	if (HAS_DDI(dev)) {
 		pipe_config->ddi_pll_sel = PORT_CLK_SEL_SPLL;
 		pipe_config->port_clock = 135000 * 2;
+
+		pipe_config->dpll_hw_state.wrpll = 0;
+		pipe_config->dpll_hw_state.spll =
+			SPLL_PLL_ENABLE | SPLL_PLL_FREQ_1350MHz | SPLL_PLL_SSC;
 	}
 
 	return true;
@@ -860,8 +839,6 @@ void intel_crt_init(struct drm_device *dev)
 	if (HAS_DDI(dev)) {
 		crt->base.get_config = hsw_crt_get_config;
 		crt->base.get_hw_state = intel_ddi_get_hw_state;
-		crt->base.pre_enable = hsw_crt_pre_enable;
-		crt->base.post_disable = hsw_crt_post_disable;
 	} else {
 		crt->base.get_config = intel_crt_get_config;
 		crt->base.get_hw_state = intel_crt_get_hw_state;