Reduce SHPD_CNT to 250us for display version 12 as it lines up with DP1.4a(Table3-4) spec. --v2 -Update commit message and comment [Matt] Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx> --- drivers/gpu/drm/i915/display/intel_hotplug_irq.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_hotplug_irq.c b/drivers/gpu/drm/i915/display/intel_hotplug_irq.c index 2c4e946d5575..8427386132e6 100644 --- a/drivers/gpu/drm/i915/display/intel_hotplug_irq.c +++ b/drivers/gpu/drm/i915/display/intel_hotplug_irq.c @@ -849,7 +849,11 @@ static void icp_hpd_irq_setup(struct drm_i915_private *dev_priv) enabled_irqs = intel_hpd_enabled_irqs(dev_priv, dev_priv->display.hotplug.pch_hpd); hotplug_irqs = intel_hpd_hotplug_irqs(dev_priv, dev_priv->display.hotplug.pch_hpd); - if (INTEL_PCH_TYPE(dev_priv) <= PCH_TGP) + /* + * We reduce the value to 250us to be able to detect SHPD when an external display + * is connected. This is also expected of us as stated in DP1.4a Table 3-4. + */ + if (INTEL_PCH_TYPE(dev_priv) < PCH_TGP) intel_uncore_write(&dev_priv->uncore, SHPD_FILTER_CNT, SHPD_FILTER_CNT_500_ADJ); else intel_uncore_write(&dev_priv->uncore, SHPD_FILTER_CNT, SHPD_FILTER_CNT_250); -- 2.43.2
