drm/i915/opregion: handle SWSCI Mailbox #2 obsoletion

Opregion Mailbox #2 is obsolete for SWSCI usage in opregion v2.x, and
repurposed in opregion v3.x. Warn about obsole mailbox presence in v2.x,
and ignore with an error for v3.x.

v2: Demote drm_warn() to drm_dbg() on opregion v2.x

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220210161603.647254-1-jani.nikula@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_opregion.c b/drivers/gpu/drm/i915/display/intel_opregion.c
index ce3d44c..11de19d 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_opregion.c
+++ b/drivers/gpu/drm/i915/display/intel_opregion.c
@@ -932,9 +932,17 @@ int intel_opregion_setup(struct drm_i915_private *dev_priv)
        }
 
        if (mboxes & MBOX_SWSCI) {
-               drm_dbg(&dev_priv->drm, "SWSCI supported\n");
-               opregion->swsci = base + OPREGION_SWSCI_OFFSET;
-               swsci_setup(dev_priv);
+               u8 major = opregion->header->over.major;
+
+               if (major >= 3) {
+                       drm_err(&dev_priv->drm, "SWSCI Mailbox #2 present for opregion v3.x, ignoring\n");
+               } else {
+                       if (major >= 2)
+                               drm_dbg(&dev_priv->drm, "SWSCI Mailbox #2 present for opregion v2.x\n");
+                       drm_dbg(&dev_priv->drm, "SWSCI supported\n");
+                       opregion->swsci = base + OPREGION_SWSCI_OFFSET;
+                       swsci_setup(dev_priv);
+               }
        }
 
        if (mboxes & MBOX_ASLE) {