Merging upstream version 6.9.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 17 insertions, 6 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
index 6083b1dcf0..a72e849ece 100644
--- a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
+++ b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
@@ -1340,16 +1340,27 @@ void dc_dmub_srv_apply_idle_power_optimizations(const struct dc *dc, bool allow_
 	 * Powering up the hardware requires notifying PMFW and DMCUB.
 	 * Clearing the driver idle allow requires a DMCUB command.
 	 * DMCUB commands requires the DMCUB to be powered up and restored.
-	 *
-	 * Exit out early to prevent an infinite loop of DMCUB commands
-	 * triggering exit low power - use software state to track this.
 	 */
-	dc_dmub_srv->idle_allowed = allow_idle;
 
-	if (!allow_idle)
+	if (!allow_idle) {
 		dc_dmub_srv_exit_low_power_state(dc);
-	else
+		/*
+		 * Idle is considered fully exited only after the sequence above
+		 * fully completes. If we have a race of two threads exiting
+		 * at the same time then it's safe to perform the sequence
+		 * twice as long as we're not re-entering.
+		 *
+		 * Infinite command submission is avoided by using the
+		 * dm_execute_dmub_cmd submission instead of the "wake" helpers.
+		 */
+		dc_dmub_srv->idle_allowed = false;
+	} else {
+		/* Consider idle as notified prior to the actual submission to
+		 * prevent multiple entries. */
+		dc_dmub_srv->idle_allowed = true;
+
 		dc_dmub_srv_notify_idle(dc, allow_idle);
+	}
 }
 
 bool dc_wake_and_execute_dmub_cmd(const struct dc_context *ctx, union dmub_rb_cmd *cmd,