Linux 4.19.31

[thirdparty/kernel/stable-queue.git] / releases / 4.19.31 / drm-amd-display-don-t-call-dm_pp_-function-from-an-fpu-block.patch

From 59d3191f14dc18881fec1172c7096b7863622803 Mon Sep 17 00:00:00 2001
From: Harry Wentland <harry.wentland@amd.com>
Date: Wed, 30 Jan 2019 15:45:18 -0500
Subject: drm/amd/display: don't call dm_pp_ function from an fpu block

From: Harry Wentland <harry.wentland@amd.com>

commit 59d3191f14dc18881fec1172c7096b7863622803 upstream.

Powerplay functions called from dm_pp_* functions tend to do a
mutex_lock which isn't safe to do inside a kernel_fpu_begin/end block as
those will disable/enable preemption.

Rearrange the dm_pp_get_clock_levels_by_type_with_voltage calls to make
sure they happen outside of kernel_fpu_begin/end.

Cc: stable@vger.kernel.org
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/amd/display/dc/calcs/dcn_calcs.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/amd/display/dc/calcs/dcn_calcs.c
+++ b/drivers/gpu/drm/amd/display/dc/calcs/dcn_calcs.c
@@ -1347,12 +1347,12 @@ void dcn_bw_update_from_pplib(struct dc
 	struct dm_pp_clock_levels_with_voltage fclks = {0}, dcfclks = {0};
 	bool res;
 
-	kernel_fpu_begin();
-
 	/* TODO: This is not the proper way to obtain fabric_and_dram_bandwidth, should be min(fclk, memclk) */
 	res = dm_pp_get_clock_levels_by_type_with_voltage(
 			ctx, DM_PP_CLOCK_TYPE_FCLK, &fclks);
 
+	kernel_fpu_begin();
+
 	if (res)
 		res = verify_clock_values(&fclks);
 
@@ -1371,9 +1371,13 @@ void dcn_bw_update_from_pplib(struct dc
 	} else
 		BREAK_TO_DEBUGGER();
 
+	kernel_fpu_end();
+
 	res = dm_pp_get_clock_levels_by_type_with_voltage(
 			ctx, DM_PP_CLOCK_TYPE_DCFCLK, &dcfclks);
 
+	kernel_fpu_begin();
+
 	if (res)
 		res = verify_clock_values(&dcfclks);