@@ -2976,6 +2976,8 @@ static void icp_hpd_irq_setup(struct drm_i915_private *dev_priv,
hotplug_irqs = sde_ddi_mask | sde_tc_mask;
enabled_irqs = intel_hpd_enabled_irqs(dev_priv, pins);
+ I915_WRITE(SHPD_FILTER_CNT, SHPD_FILTER_CNT_500_ADJ);
+
ibx_display_interrupt_update(dev_priv, hotplug_irqs, enabled_irqs);
icp_hpd_detection_setup(dev_priv, ddi_enable_mask, tc_enable_mask);
@@ -3081,6 +3083,9 @@ static void spt_hpd_irq_setup(struct drm_i915_private *dev_priv)
{
u32 hotplug_irqs, enabled_irqs;
+ if (INTEL_PCH_TYPE(dev_priv) >= PCH_CNP)
+ I915_WRITE(SHPD_FILTER_CNT, SHPD_FILTER_CNT_500_ADJ);
+
hotplug_irqs = SDE_HOTPLUG_MASK_SPT;
enabled_irqs = intel_hpd_enabled_irqs(dev_priv, hpd_spt);
@@ -8083,6 +8083,10 @@ enum {
#define SHOTPLUG_CTL_TC _MMIO(0xc4034)
#define ICP_TC_HPD_ENABLE(tc_port) (8 << (tc_port) * 4)
+
+#define SHPD_FILTER_CNT _MMIO(0xc4038)
+#define SHPD_FILTER_CNT_500_ADJ 0x001D9
+
/* Icelake DSC Rate Control Range Parameter Registers */
#define DSCA_RC_RANGE_PARAMETERS_0 _MMIO(0x6B240)
#define DSCA_RC_RANGE_PARAMETERS_0_UDW _MMIO(0x6B240 + 4)
The bspec tells us 'Program SHPD_FILTER_CNT with the "500 microseconds adjusted" value before enabling hotplug detection' on CNP+. We haven't been touching this register at all thus far, but we should probably follow the bspec's guidance. The register also exists on LPT and SPT, but there isn't any specific guidance I can find on how we should be programming it there so let's leave it be for now. Bspec: 4342 Bspec: 31297 Bspec: 8407 Bspec: 49305 Bspec: 50473 Signed-off-by: Matt Roper <matthew.d.roper@intel.com> --- drivers/gpu/drm/i915/i915_irq.c | 5 +++++ drivers/gpu/drm/i915/i915_reg.h | 4 ++++ 2 files changed, 9 insertions(+)