linux-kernel - [PATCH v1] drm/bridge: ti-sn65dsi86: Transition to LP mode on every video line

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Message-ID: <20250916142047.3582018-1-ghidoliemanuele@gmail.com>
Date: Tue, 16 Sep 2025 16:20:43 +0200
From: Emanuele Ghidoli <ghidoliemanuele@...il.com>
To: 
Cc: Emanuele Ghidoli <emanuele.ghidoli@...adex.com>,
	Douglas Anderson <dianders@...omium.org>,
	Andrzej Hajda <andrzej.hajda@...el.com>,
	Neil Armstrong <neil.armstrong@...aro.org>,
	Robert Foss <rfoss@...nel.org>,
	Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
	Jonas Karlman <jonas@...boo.se>,
	Jernej Skrabec <jernej.skrabec@...il.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>,
	Jayesh Choudhary <j-choudhary@...com>,
	dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH v1] drm/bridge: ti-sn65dsi86: Transition to LP mode on every video line

From: Emanuele Ghidoli <emanuele.ghidoli@...adex.com>

The component datasheet recommends, to reduce power consumption,
transitioning to LP mode on every video line.

Enable the MIPI_DSI_MODE_VIDEO_NO_HFP and MIPI_DSI_MODE_VIDEO_NO_HBP
flags so that the bridge can enter LP mode during the horizontal front
porch and back porch periods.

Signed-off-by: Emanuele Ghidoli <emanuele.ghidoli@...adex.com>
---
Cc: Douglas Anderson <dianders@...omium.org>
Cc: Andrzej Hajda <andrzej.hajda@...el.com>
Cc: Neil Armstrong <neil.armstrong@...aro.org>
Cc: Robert Foss <rfoss@...nel.org>
Cc: Laurent Pinchart <Laurent.pinchart@...asonboard.com>
Cc: Jonas Karlman <jonas@...boo.se>
Cc: Jernej Skrabec <jernej.skrabec@...il.com>
Cc: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>
Cc: Maxime Ripard <mripard@...nel.org>
Cc: Thomas Zimmermann <tzimmermann@...e.de>
Cc: David Airlie <airlied@...il.com>
Cc: Simona Vetter <simona@...ll.ch>
Cc: Jayesh Choudhary <j-choudhary@...com>
Cc: <dri-devel@...ts.freedesktop.org>
Cc: <linux-kernel@...r.kernel.org>
---
 drivers/gpu/drm/bridge/ti-sn65dsi86.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
index ae0d08e5e960..957e9abd46c3 100644
--- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
@@ -689,7 +689,8 @@ static int ti_sn_attach_host(struct auxiliary_device *adev, struct ti_sn65dsi86
 	/* TODO: setting to 4 MIPI lanes always for now */
 	dsi->lanes = 4;
 	dsi->format = MIPI_DSI_FMT_RGB888;
-	dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_NO_HFP |
+			  MIPI_DSI_MODE_VIDEO_NO_HBP;
 
 	/* check if continuous dsi clock is required or not */
 	pm_runtime_get_sync(dev);
-- 
2.43.0