Re: [PATCH 13/16] drm/i915: Fix DVO 2x clock enable on 830M

Daniel Vetter
2014-09-01T08:46:21Z

On Fri, Aug 15, 2014 at 01:22:05AM +0300, ville.syrjala@linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> The spec says:
> "For the correct operation of the muxed DVO pins (GDEVSELB/ I2Cdata,
> GIRDBY/I2CClk) and (GFRAMEB/DVI_Data, GTRDYB/DVI_Clk): Bit 31
> (DPLL VCO Enable) and Bit 30 (2X Clock Enable) must be set to “1” in
> both the DPLL A Control Register (06014h-06017h) and DPLL B Control
> Register (06018h-0601Bh)."
>
> The pipe A and B force quirks take care of DPLL_VCO_ENABLE, so we
> just need a bit of special care to handle DPLL_DVO_2X_MODE.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 3 +++
> drivers/gpu/drm/i915/intel_display.c | 47 +++++++++++++++++++++++++++++++++---
> 2 files changed, 46 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 541fb6f..54895a6 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1561,6 +1561,9 @@ struct drm_i915_private {
>
> u16 orig_clock;
>
> + /* used to control DVO 2x clock enable on 830M */
> + uint8_t dvo_pipes;
> +
> bool mchbar_need_disable;
>
> struct intel_l3_parity l3_parity;
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 3eeb5ce..6462bcf 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -1548,6 +1548,7 @@ static void i9xx_enable_pll(struct intel_crtc *crtc)
> {
> struct drm_device *dev = crtc->base.dev;
> struct drm_i915_private *dev_priv = dev->dev_private;
> + enum pipe pipe = crtc->pipe;
> int reg = DPLL(crtc->pipe);
> u32 dpll = crtc->config.dpll_hw_state.dpll;
>
> @@ -1560,7 +1561,16 @@ static void i9xx_enable_pll(struct intel_crtc *crtc)
> if (IS_MOBILE(dev) && !IS_I830(dev))
> assert_panel_unlocked(dev_priv, crtc->pipe);
>
> - I915_WRITE(reg, dpll);
> + /* enable DVO 2x clock on both PLLs if necessary */
> + if (IS_I830(dev)) {
> + if (intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_DVO))
> + dev_priv->dvo_pipes |= 1 << pipe;
> +
> + if (dev_priv->dvo_pipes) {
> + dpll |= DPLL_DVO_2X_MODE;
> + I915_WRITE(DPLL(!pipe), I915_READ(DPLL(!pipe)) | DPLL_DVO_2X_MODE);
> + }
> + }
>
> /* Wait for the clocks to stabilize. */
> POSTING_READ(reg);
> @@ -1599,8 +1609,23 @@ static void i9xx_enable_pll(struct intel_crtc *crtc)
> *
> * Note! This is for pre-ILK only.
> */
> -static void i9xx_disable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
> +static void i9xx_disable_pll(struct intel_crtc *crtc)
> {
> + struct drm_device *dev = crtc->base.dev;
> + struct drm_i915_private *dev_priv = dev->dev_private;
> + enum pipe pipe = crtc->pipe;
> +
> + /* disable DVO 2x clock on both PLLs if necessary */
> + if (IS_I830(dev)) {
> + if (intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_DVO))
> + dev_priv->dvo_pipes &= ~(1 << pipe);
> +
> + if (!dev_priv->dvo_pipes) {
> + I915_WRITE(DPLL(pipe), I915_READ(DPLL(pipe)) & ~DPLL_DVO_2X_MODE);
> + I915_WRITE(DPLL(!pipe), I915_READ(DPLL(!pipe)) & ~DPLL_DVO_2X_MODE);

Bikeshed: I'd just use explicit PIPE_A and PIPE_B here, except when we
really have to turn of our pipe first before the other.

> + }
> + }
> +
> /* Don't disable pipe A or pipe A PLLs if needed */
> if (pipe == PIPE_A && (dev_priv->quirks & QUIRK_PIPEA_FORCE))
> return;
> @@ -4788,7 +4813,7 @@ static void i9xx_crtc_disable(struct drm_crtc *crtc)
> else if (IS_VALLEYVIEW(dev))
> vlv_disable_pll(dev_priv, pipe);
> else
> - i9xx_disable_pll(dev_priv, pipe);
> + i9xx_disable_pll(intel_crtc);
> }
>
> if (!IS_GEN2(dev))
> @@ -5792,7 +5817,7 @@ static void i8xx_update_pll(struct intel_crtc *crtc,
> dpll |= PLL_P2_DIVIDE_BY_4;
> }
>
> - if (intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_DVO))
> + if (!IS_I830(dev) && intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_DVO))
> dpll |= DPLL_DVO_2X_MODE;
>
> if (intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_LVDS) &&
> @@ -6298,6 +6323,9 @@ static bool i9xx_get_pipe_config(struct intel_crtc *crtc,
> }
> pipe_config->dpll_hw_state.dpll = I915_READ(DPLL(crtc->pipe));
> if (!IS_VALLEYVIEW(dev)) {
> + if (IS_I830(dev))
> + pipe_config->dpll_hw_state.dpll &= ~DPLL_DVO_2X_MODE;
> +
> pipe_config->dpll_hw_state.fp0 = I915_READ(FP0(crtc->pipe));
> pipe_config->dpll_hw_state.fp1 = I915_READ(FP1(crtc->pipe));
> } else {
> @@ -13021,6 +13049,17 @@ void intel_modeset_setup_hw_state(struct drm_device *dev,
> }
> }
>
> + /* update dvo_pipes */
> + if (IS_I830(dev)) {
> + dev_priv->dvo_pipes = 0;
> +
> + for_each_intel_crtc(dev, crtc) {
> + if (crtc->active &&
> + intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_DVO))
> + dev_priv->dvo_pipes |= 1 << crtc->pipe;
> + }
> + }

This puts gunk into the modeset hw state stuff. Imo just loop over all
pipes and recompute the i830_needs_dvo_2x everywhere you need it, instead
of adding a new dev_priv->dvo_pipes state which might get out of sync
eventually.

I'll punt on this for now.
-Daniel

> +
> /* HW state is read out, now we need to sanitize this mess. */
> for_each_intel_encoder(dev, encoder) {
> intel_sanitize_encoder(encoder);
> --
> 1.8.5.5
>
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--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch