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From: Michael Walle <mwalle@kernel.org>
Date: Mon, 06 May 2024 15:34:31 +0200
Subject: [PATCH 02/20] drm/mediatek: dsi: provide LP-11 mode during
 .pre_enable
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Message-Id: <20240506-tc358775-fix-powerup-v1-2-545dcf00b8dd@kernel.org>
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To: Andrzej Hajda <andrzej.hajda@intel.com>, 
 Neil Armstrong <neil.armstrong@linaro.org>, Robert Foss <rfoss@kernel.org>, 
 Laurent Pinchart <Laurent.pinchart@ideasonboard.com>, 
 Jonas Karlman <jonas@kwiboo.se>, Jernej Skrabec <jernej.skrabec@gmail.com>, 
 Maarten Lankhorst <maarten.lankhorst@linux.intel.com>, 
 Maxime Ripard <mripard@kernel.org>, Thomas Zimmermann <tzimmermann@suse.de>, 
 David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>, 
 Chun-Kuang Hu <chunkuang.hu@kernel.org>, 
 Philipp Zabel <p.zabel@pengutronix.de>, 
 Matthias Brugger <matthias.bgg@gmail.com>, 
 AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>, 
 Sam Ravnborg <sam@ravnborg.org>, Vinay Simha BN <simhavcs@gmail.com>, 
 Tony Lindgren <tony@atomide.com>
Cc: Daniel Semkowicz <dse@thaumatec.com>, dri-devel@lists.freedesktop.org, 
 linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, 
 linux-arm-kernel@lists.infradead.org, Michael Walle <mwalle@kernel.org>

As per specification in drivers/gpu/drm/drm_bridge.c the data lanes
should be in LP-11 mode after .pre_enable() has been run. HS mode of the
data lanes are enabled with mtk_dsi_start(). Therefore, move that call
to the .enable() callback.

Signed-off-by: Michael Walle <mwalle@kernel.org>
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index c255559cc56e..ed45c9cc3137 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -711,8 +711,6 @@ static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
 	mtk_dsi_set_mode(dsi);
 	mtk_dsi_clk_hs_mode(dsi, 1);
 
-	mtk_dsi_start(dsi);
-
 	dsi->enabled = true;
 }
 
@@ -759,7 +757,7 @@ static void mtk_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
 	if (dsi->refcount == 0)
 		return;
 
-	mtk_output_dsi_enable(dsi);
+	mtk_dsi_start(dsi);
 }
 
 static void mtk_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge,
@@ -771,6 +769,9 @@ static void mtk_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge,
 	ret = mtk_dsi_poweron(dsi);
 	if (ret < 0)
 		DRM_ERROR("failed to power on dsi\n");
+
+	/* Enter LP-11 state */
+	mtk_output_dsi_enable(dsi);
 }
 
 static void mtk_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge,

-- 
2.39.2