drm/i915: Program SHPD_FILTER_CNT on CNP+
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>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191127221314.575575-3-matthew.d.roper@intel.com
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index a99fdf8..1a6376a 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8114,6 +8114,10 @@ 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)
