[Intel-gfx] [PATCH 1/9] drm/i915: Keep GMCH DPLL VGA mode always disabled
Sivakumar Thulasimani
sivakumar.thulasimani at intel.com
Mon Jun 29 07:16:18 PDT 2015
On 6/29/2015 5:55 PM, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> We disable the DPLL VGA mode when enabling the DPLL, but we enaable it
> again when disabling the DPLL. Having VGA mode enabled even in unused
> DPLLs can cause problems for CHV, so it seems wiser to always keep it
> disabled. And let's just do that on all GMCH platforms to keep things
> as similar as possible between them.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
> drivers/gpu/drm/i915/intel_display.c | 8 +++++---
> drivers/gpu/drm/i915/intel_dsi.c | 2 +-
> drivers/gpu/drm/i915/intel_runtime_pm.c | 8 ++++----
> 3 files changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index d624f58..dd3b649 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -1774,13 +1774,13 @@ static void i9xx_disable_pll(struct intel_crtc *crtc)
> /* Make sure the pipe isn't still relying on us */
> assert_pipe_disabled(dev_priv, pipe);
>
> - I915_WRITE(DPLL(pipe), 0);
> + I915_WRITE(DPLL(pipe), DPLL_VGA_MODE_DIS);
> POSTING_READ(DPLL(pipe));
> }
>
> static void vlv_disable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
> {
> - u32 val = 0;
> + u32 val;
>
> /* Make sure the pipe isn't still relying on us */
> assert_pipe_disabled(dev_priv, pipe);
> @@ -1789,6 +1789,7 @@ static void vlv_disable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
> * Leave integrated clock source and reference clock enabled for pipe B.
> * The latter is needed for VGA hotplug / manual detection.
> */
> + val = DPLL_VGA_MODE_DIS;
> if (pipe == PIPE_B)
> val = DPLL_INTEGRATED_CRI_CLK_VLV | DPLL_REFA_CLK_ENABLE_VLV;
> I915_WRITE(DPLL(pipe), val);
> @@ -1805,7 +1806,8 @@ static void chv_disable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
> assert_pipe_disabled(dev_priv, pipe);
>
> /* Set PLL en = 0 */
> - val = DPLL_SSC_REF_CLOCK_CHV | DPLL_REFA_CLK_ENABLE_VLV;
> + val = DPLL_SSC_REF_CLOCK_CHV |
> + DPLL_REFA_CLK_ENABLE_VLV | DPLL_VGA_MODE_DIS;
> if (pipe != PIPE_A)
> val |= DPLL_INTEGRATED_CRI_CLK_VLV;
> I915_WRITE(DPLL(pipe), val);
> diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
> index 3f29385..e087360 100644
> --- a/drivers/gpu/drm/i915/intel_dsi.c
> +++ b/drivers/gpu/drm/i915/intel_dsi.c
> @@ -427,7 +427,7 @@ static void intel_dsi_pre_enable(struct intel_encoder *encoder)
>
> /* update the hw state for DPLL */
> intel_crtc->config->dpll_hw_state.dpll = DPLL_INTEGRATED_CLOCK_VLV |
> - DPLL_REFA_CLK_ENABLE_VLV;
> + DPLL_REFA_CLK_ENABLE_VLV | DPLL_VGA_MODE_DIS;
>
> tmp = I915_READ(DSPCLK_GATE_D);
> tmp |= DPOUNIT_CLOCK_GATE_DISABLE;
> diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
> index 1a45385..f0e6f49 100644
> --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> @@ -882,7 +882,7 @@ static void vlv_dpio_cmn_power_well_enable(struct drm_i915_private *dev_priv,
> * display and the reference clock for VGA
> * hotplug / manual detection.
> */
> - I915_WRITE(DPLL(PIPE_B), I915_READ(DPLL(PIPE_B)) |
> + I915_WRITE(DPLL(PIPE_B), I915_READ(DPLL(PIPE_B)) | DPLL_VGA_MODE_DIS |
> DPLL_REFA_CLK_ENABLE_VLV | DPLL_INTEGRATED_CRI_CLK_VLV);
> udelay(1); /* >10ns for cmnreset, >0ns for sidereset */
>
> @@ -933,13 +933,13 @@ static void chv_dpio_cmn_power_well_enable(struct drm_i915_private *dev_priv,
> */
> if (power_well->data == PUNIT_POWER_WELL_DPIO_CMN_BC) {
> phy = DPIO_PHY0;
> - I915_WRITE(DPLL(PIPE_B), I915_READ(DPLL(PIPE_B)) |
> + I915_WRITE(DPLL(PIPE_B), I915_READ(DPLL(PIPE_B)) | DPLL_VGA_MODE_DIS |
> DPLL_REFA_CLK_ENABLE_VLV);
> - I915_WRITE(DPLL(PIPE_B), I915_READ(DPLL(PIPE_B)) |
> + I915_WRITE(DPLL(PIPE_B), I915_READ(DPLL(PIPE_B)) | DPLL_VGA_MODE_DIS |
> DPLL_REFA_CLK_ENABLE_VLV | DPLL_INTEGRATED_CRI_CLK_VLV);
> } else {
> phy = DPIO_PHY1;
> - I915_WRITE(DPLL(PIPE_C), I915_READ(DPLL(PIPE_C)) |
> + I915_WRITE(DPLL(PIPE_C), I915_READ(DPLL(PIPE_C)) | DPLL_VGA_MODE_DIS |
> DPLL_REFA_CLK_ENABLE_VLV | DPLL_INTEGRATED_CRI_CLK_VLV);
> }
> udelay(1); /* >10ns for cmnreset, >0ns for sidereset */
since we keep DPLL_VGA_MODE_DIS always set, even during disable is this
needed explicitly again here ? other than this i am fine with this.
Reviewed-by: Sivakumar Thulasimani <sivakumar.thulasimani at intel.com>
--
regards,
Sivakumar
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