drm/i915/guc: improve documentation
Add a short description of what we expect from GuC and some minor
improvements to existing documentation. Also remove a comment about a
difference between GuC and HuC that is not true anymore.
v2: add that the GuC is not mandatory (Martin)
v3: add extra newline for better text organization (Martin)
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Martin Peres <martin.peres@linux.intel.com>
Acked-by: Anna Karas <anna.karas@intel.com>
Reviewed-by: Martin Peres <martin.peres@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191014183602.3643-2-daniele.ceraolospurio@intel.com
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index f325d3d..849a44a 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -29,6 +29,12 @@ enum {
/**
* DOC: GuC-based command submission
*
+ * IMPORTANT NOTE: GuC submission is currently not supported in i915. The GuC
+ * firmware is moving to an updated submission interface and we plan to
+ * turn submission back on when that lands. The below documentation (and related
+ * code) matches the old submission model and will be updated as part of the
+ * upgrade to the new flow.
+ *
* GuC client:
* A intel_guc_client refers to a submission path through GuC. Currently, there
* is only one client, which is charged with all submissions to the GuC. This
