releases/5.9.5/drm-amd-display-check-clock-table-return.patch

From ea66d3f1d7467b31a4d9f51fd46c545c12b3210b Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Thu, 20 Aug 2020 14:26:07 -0400
Subject: drm/amd/display: Check clock table return

From: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>

[ Upstream commit 4b4f21ff7f5d11bb77e169b306dcbc5b216f5db5 ]

During the load processes for Renoir, our display code needs to retrieve
the SMU clock and voltage table, however, this operation can fail which
means that we have to check this scenario. Currently, we are not
handling this case properly and as a result, we have seen the following
dmesg log during the boot:

RIP: 0010:rn_clk_mgr_construct+0x129/0x3d0 [amdgpu]
...
Call Trace:
 dc_clk_mgr_create+0x16a/0x1b0 [amdgpu]
 dc_create+0x231/0x760 [amdgpu]

This commit fixes this issue by checking the return status retrieved
from the clock table before try to populate any bandwidth.

Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c
index 21a3073c8929e..2f8fee05547ac 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c
@@ -761,6 +761,7 @@ void rn_clk_mgr_construct(
 {
 	struct dc_debug_options *debug = &ctx->dc->debug;
 	struct dpm_clocks clock_table = { 0 };
+	enum pp_smu_status status = 0;
 
 	clk_mgr->base.ctx = ctx;
 	clk_mgr->base.funcs = &dcn21_funcs;
@@ -817,8 +818,10 @@ void rn_clk_mgr_construct(
 	clk_mgr->base.bw_params = &rn_bw_params;
 
 	if (pp_smu && pp_smu->rn_funcs.get_dpm_clock_table) {
-		pp_smu->rn_funcs.get_dpm_clock_table(&pp_smu->rn_funcs.pp_smu, &clock_table);
-		if (ctx->dc_bios && ctx->dc_bios->integrated_info) {
+		status = pp_smu->rn_funcs.get_dpm_clock_table(&pp_smu->rn_funcs.pp_smu, &clock_table);
+
+		if (status == PP_SMU_RESULT_OK &&
+		    ctx->dc_bios && ctx->dc_bios->integrated_info) {
 			rn_clk_mgr_helper_populate_bw_params (clk_mgr->base.bw_params, &clock_table, ctx->dc_bios->integrated_info);
 		}
 	}
-- 
2.27.0