Re: [PATCH v2 13/16] drm/i915: Fix DVO 2x clock enable on 830M

Daniel Vetter
2014-09-08T07:32:46Z

On Fri, Sep 05, 2014 at 09:52:42PM +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.
>
> v2: Recompute num_dvo_pipes on the spot, use PIPE_A/PIPE_B instead
> of pipe/!pipe for the register offsets in disable (Daniel)
> Add a comment about the ordering in enable and another one
> about filtering out the DVO 2x bit in state readout
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Queued for -next, thanks for the patch.
-Daniel

> ---
> drivers/gpu/drm/i915/intel_display.c | 53 +++++++++++++++++++++++++++++++++---
> 1 file changed, 49 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 842a5e1..6d6214a 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -1612,6 +1612,18 @@ static void chv_enable_pll(struct intel_crtc *crtc)
> mutex_unlock(&dev_priv->dpio_lock);
> }
>
> +static int intel_num_dvo_pipes(struct drm_device *dev)
> +{
> + struct intel_crtc *crtc;
> + int count = 0;
> +
> + for_each_intel_crtc(dev, crtc)
> + count += crtc->active &&
> + intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_DVO);
> +
> + return count;
> +}
> +
> static void i9xx_enable_pll(struct intel_crtc *crtc)
> {
> struct drm_device *dev = crtc->base.dev;
> @@ -1628,7 +1640,18 @@ 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) && intel_num_dvo_pipes(dev) > 0) {
> + /*
> + * It appears to be important that we don't enable this
> + * for the current pipe before otherwise configuring the
> + * PLL. No idea how this should be handled if multiple
> + * DVO outputs are enabled simultaneosly.
> + */
> + dpll |= DPLL_DVO_2X_MODE;
> + I915_WRITE(DPLL(!crtc->pipe),
> + I915_READ(DPLL(!crtc->pipe)) | DPLL_DVO_2X_MODE);
> + }
>
> /* Wait for the clocks to stabilize. */
> POSTING_READ(reg);
> @@ -1667,8 +1690,22 @@ 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) &&
> + intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_DVO) &&
> + intel_num_dvo_pipes(dev) == 1) {
> + I915_WRITE(DPLL(PIPE_B),
> + I915_READ(DPLL(PIPE_B)) & ~DPLL_DVO_2X_MODE);
> + I915_WRITE(DPLL(PIPE_A),
> + I915_READ(DPLL(PIPE_A)) & ~DPLL_DVO_2X_MODE);
> + }
> +
> /* Don't disable pipe or pipe PLLs if needed */
> if ((pipe == PIPE_A && dev_priv->quirks & QUIRK_PIPEA_FORCE) ||
> (pipe == PIPE_B && dev_priv->quirks & QUIRK_PIPEB_FORCE))
> @@ -4940,7 +4977,7 @@ 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))
> @@ -5944,7 +5981,7 @@ 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) &&
> @@ -6450,6 +6487,14 @@ 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)) {
> + /*
> + * DPLL_DVO_2X_MODE must be enabled for both DPLLs
> + * on 830. Filter it out here so that we don't
> + * report errors due to that.
> + */
> + 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 {
> --
> 1.8.5.5
>

--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch