drm/i915: Per-DDI I_boost override
An OEM may request increased I_boost beyond the recommended values
by specifying an I_boost value to be applied to all swing entries for
a port. These override values are specified in VBT.
v2: rebase and remove unused iboost_bit variable
Issue: VIZ-5676
Signed-off-by: Antti Koskipaa <antti.koskipaa@linux.intel.com>
Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 990acc2..8e46149 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -886,6 +886,17 @@
memset(dev_priv->vbt.dsi.sequence, 0, sizeof(dev_priv->vbt.dsi.sequence));
}
+static u8 translate_iboost(u8 val)
+{
+ static const u8 mapping[] = { 1, 3, 7 }; /* See VBT spec */
+
+ if (val >= ARRAY_SIZE(mapping)) {
+ DRM_DEBUG_KMS("Unsupported I_boost value found in VBT (%d), display may not work properly\n", val);
+ return 0;
+ }
+ return mapping[val];
+}
+
static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
const struct bdb_header *bdb)
{
@@ -1001,6 +1012,16 @@
hdmi_level_shift);
info->hdmi_level_shift = hdmi_level_shift;
}
+
+ /* Parse the I_boost config for SKL and above */
+ if (bdb->version >= 196 && (child->common.flags_1 & IBOOST_ENABLE)) {
+ info->dp_boost_level = translate_iboost(child->common.iboost_level & 0xF);
+ DRM_DEBUG_KMS("VBT (e)DP boost level for port %c: %d\n",
+ port_name(port), info->dp_boost_level);
+ info->hdmi_boost_level = translate_iboost(child->common.iboost_level >> 4);
+ DRM_DEBUG_KMS("VBT HDMI boost level for port %c: %d\n",
+ port_name(port), info->hdmi_boost_level);
+ }
}
static void parse_ddi_ports(struct drm_i915_private *dev_priv,