From c038e51e841581cc3fb9a76e5e16331331e9c85c Mon Sep 17 00:00:00 2001 From: Zhenyu Wang Date: Mon, 19 Oct 2009 15:43:48 +0800 Subject: drm/i915: fix to setup display reference clock control on Ironlake For new stepping of PCH, the display reference clock is fully under driver's control. This one trys to setup all needed reference clock for different outputs. Older stepping of PCH chipset should be ignoring this. This fixes output failure issue on newer PCH which requires driver to take control of reference clock enabling. Cc: Stable Team Signed-off-by: Zhenyu Wang Signed-off-by: Eric Anholt --- drivers/gpu/drm/i915/intel_display.c | 40 ++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) (limited to 'drivers/gpu/drm/i915/intel_display.c') diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 123cce1ae470..db4c38700951 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2814,6 +2814,46 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc, link_bw, &m_n); } + /* Ironlake: try to setup display ref clock before DPLL + * enabling. This is only under driver's control after + * PCH B stepping, previous chipset stepping should be + * ignoring this setting. + */ + if (IS_IGDNG(dev)) { + temp = I915_READ(PCH_DREF_CONTROL); + /* Always enable nonspread source */ + temp &= ~DREF_NONSPREAD_SOURCE_MASK; + temp |= DREF_NONSPREAD_SOURCE_ENABLE; + I915_WRITE(PCH_DREF_CONTROL, temp); + POSTING_READ(PCH_DREF_CONTROL); + + temp &= ~DREF_SSC_SOURCE_MASK; + temp |= DREF_SSC_SOURCE_ENABLE; + I915_WRITE(PCH_DREF_CONTROL, temp); + POSTING_READ(PCH_DREF_CONTROL); + + udelay(200); + + if (is_edp) { + if (dev_priv->lvds_use_ssc) { + temp |= DREF_SSC1_ENABLE; + I915_WRITE(PCH_DREF_CONTROL, temp); + POSTING_READ(PCH_DREF_CONTROL); + + udelay(200); + + temp &= ~DREF_CPU_SOURCE_OUTPUT_MASK; + temp |= DREF_CPU_SOURCE_OUTPUT_DOWNSPREAD; + I915_WRITE(PCH_DREF_CONTROL, temp); + POSTING_READ(PCH_DREF_CONTROL); + } else { + temp |= DREF_CPU_SOURCE_OUTPUT_NONSPREAD; + I915_WRITE(PCH_DREF_CONTROL, temp); + POSTING_READ(PCH_DREF_CONTROL); + } + } + } + if (IS_IGD(dev)) { fp = (1 << clock.n) << 16 | clock.m1 << 8 | clock.m2; if (has_reduced_clock) -- cgit v1.2.3