releases/6.16.2/drm-amd-display-update-dmcub-loading-sequence-for-dc.patch

From 7e153665be13707b31bab5d7ce170baa58b9143b Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Fri, 9 May 2025 11:18:26 -0400
Subject: drm/amd/display: Update DMCUB loading sequence for DCN3.5

From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>

[ Upstream commit d42b2331e158fa6bcdc89e4c8c470dc5da20be1f ]

[Why]
New sequence from HW for reset and firmware reloading has been
provided that aims to stabilize the reload sequence in the case the
firmware is hung or has outstanding requests.

[How]
Update the sequence to remove the DMUIF reset and the redundant
writes in the release.

Reviewed-by: Ovidiu Bunea <ovidiu.bunea@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../gpu/drm/amd/display/dmub/src/dmub_dcn35.c    | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn35.c b/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn35.c
index 72a0f078cd1a..2884977a3dd2 100644
--- a/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn35.c
+++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_dcn35.c
@@ -92,19 +92,15 @@ void dmub_dcn35_reset(struct dmub_srv *dmub)
 	uint32_t in_reset, is_enabled, scratch, i, pwait_mode;
 
 	REG_GET(DMCUB_CNTL2, DMCUB_SOFT_RESET, &in_reset);
+	REG_GET(DMCUB_CNTL, DMCUB_ENABLE, &is_enabled);
 
-	if (in_reset == 0) {
+	if (in_reset == 0 && is_enabled != 0) {
 		cmd.bits.status = 1;
 		cmd.bits.command_code = DMUB_GPINT__STOP_FW;
 		cmd.bits.param = 0;
 
 		dmub->hw_funcs.set_gpint(dmub, cmd);
 
-		/**
-		 * Timeout covers both the ACK and the wait
-		 * for remaining work to finish.
-		 */
-
 		for (i = 0; i < timeout; ++i) {
 			if (dmub->hw_funcs.is_gpint_acked(dmub, cmd))
 				break;
@@ -130,11 +126,9 @@ void dmub_dcn35_reset(struct dmub_srv *dmub)
 		/* Force reset in case we timed out, DMCUB is likely hung. */
 	}
 
-	REG_GET(DMCUB_CNTL, DMCUB_ENABLE, &is_enabled);
-
 	if (is_enabled) {
 		REG_UPDATE(DMCUB_CNTL2, DMCUB_SOFT_RESET, 1);
-		REG_UPDATE(MMHUBBUB_SOFT_RESET, DMUIF_SOFT_RESET, 1);
+		udelay(1);
 		REG_UPDATE(DMCUB_CNTL, DMCUB_ENABLE, 0);
 	}
 
@@ -160,11 +154,7 @@ void dmub_dcn35_reset_release(struct dmub_srv *dmub)
 		     LONO_SOCCLK_GATE_DISABLE, 1,
 		     LONO_DMCUBCLK_GATE_DISABLE, 1);
 
-	REG_UPDATE(MMHUBBUB_SOFT_RESET, DMUIF_SOFT_RESET, 1);
-	udelay(1);
 	REG_UPDATE_2(DMCUB_CNTL, DMCUB_ENABLE, 1, DMCUB_TRACEPORT_EN, 1);
-	REG_UPDATE(DMCUB_CNTL2, DMCUB_SOFT_RESET, 1);
-	udelay(1);
 	REG_UPDATE(MMHUBBUB_SOFT_RESET, DMUIF_SOFT_RESET, 0);
 	REG_UPDATE(DMCUB_CNTL2, DMCUB_SOFT_RESET, 0);
 }
-- 
2.39.5