linux-kernel - [PATCH] drm/amd/display: do not allocate display_mode

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Date:   Sat,  4 Jan 2020 14:22:15 +0200
From:   Dor Askayo <dor.askayo@...il.com>
To:     amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org
Cc:     Dor Askayo <dor.askayo@...il.com>,
        Harry Wentland <harry.wentland@....com>,
        Leo Li <sunpeng.li@....com>,
        Alex Deucher <alexander.deucher@....com>,
        Christian König <christian.koenig@....com>,
        "David (ChunMing) Zhou" <David1.Zhou@....com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>
Subject: [PATCH] drm/amd/display: do not allocate display_mode_lib unnecessarily

This allocation isn't required and can fail when resuming from suspend.

Bug: https://gitlab.freedesktop.org/drm/amd/issues/1009
Signed-off-by: Dor Askayo <dor.askayo@...il.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index dd4731ab935c..83ebb716166b 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -2179,12 +2179,7 @@ void dc_set_power_state(
 	enum dc_acpi_cm_power_state power_state)
 {
 	struct kref refcount;
-	struct display_mode_lib *dml = kzalloc(sizeof(struct display_mode_lib),
-						GFP_KERNEL);
-
-	ASSERT(dml);
-	if (!dml)
-		return;
+	struct display_mode_lib *dml;
 
 	switch (power_state) {
 	case DC_ACPI_CM_POWER_STATE_D0:
@@ -2206,6 +2201,12 @@ void dc_set_power_state(
 		 * clean state, and dc hw programming optimizations will not
 		 * cause any trouble.
 		 */
+		dml = kzalloc(sizeof(struct display_mode_lib),
+				GFP_KERNEL);
+
+		ASSERT(dml);
+		if (!dml)
+			return;
 
 		/* Preserve refcount */
 		refcount = dc->current_state->refcount;
@@ -2219,10 +2220,10 @@ void dc_set_power_state(
 		dc->current_state->refcount = refcount;
 		dc->current_state->bw_ctx.dml = *dml;
 
+		kfree(dml);
+
 		break;
 	}
-
-	kfree(dml);
 }
 
 void dc_resume(struct dc *dc)
-- 
2.24.1