linux-kernel - [PATCH 2/2] drm: mediatek: mtk_drm_crtc: Use kmalloc in mtk_drm_crtc_duplicate

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Date:   Tue, 18 Jan 2022 14:37:59 +0100
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>
To:     chunkuang.hu@...nel.org
Cc:     p.zabel@...gutronix.de, airlied@...ux.ie, daniel@...ll.ch,
        matthias.bgg@...il.com, dri-devel@...ts.freedesktop.org,
        linux-mediatek@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        kernel@...labora.com,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>
Subject: [PATCH 2/2] drm: mediatek: mtk_drm_crtc: Use kmalloc in mtk_drm_crtc_duplicate_state

Optimize mtk_drm_crtc_duplicate_state() by switching from kzalloc() to
kmalloc(): the only variable of this struct that gets checked in other
functions is `pending_config`, but if that's set to false, then all of
the remaining variables will only ever be set, but not read - so, also
set `pending_config` to false.
This saves us some small overhead.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index 09fc9ad02c7a..f536a0a927e4 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -185,7 +185,7 @@ static struct drm_crtc_state *mtk_drm_crtc_duplicate_state(struct drm_crtc *crtc
 {
 	struct mtk_crtc_state *state;
 
-	state = kzalloc(sizeof(*state), GFP_KERNEL);
+	state = kmalloc(sizeof(*state), GFP_KERNEL);
 	if (!state)
 		return NULL;
 
@@ -193,6 +193,7 @@ static struct drm_crtc_state *mtk_drm_crtc_duplicate_state(struct drm_crtc *crtc
 
 	WARN_ON(state->base.crtc != crtc);
 	state->base.crtc = crtc;
+	state->pending_config = false;
 
 	return &state->base;
 }
-- 
2.33.1