From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Date: Wed, 18 Jan 2023 10:16:47 +0200

Subject: [PATCH] drm/bridge: lt9611: fix HPD reenablement

References: bsc#1012628

Patch-mainline: 6.2.3

Git-commit: a7790f6bd38f3642b60ae3504a2c749135b89451

[ Upstream commit a7790f6bd38f3642b60ae3504a2c749135b89451 ]

The driver will reset the bridge in the atomic_pre_enable(). However

this will also drop the HPD interrupt state. Instead of resetting the

bridge, properly wake it up. This fixes the HPD interrupt delivery after

the disable/enable cycle.

Fixes: 23278bf54afe ("drm/bridge: Introduce LT9611 DSI to HDMI bridge")

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>

Link: https://patchwork.freedesktop.org/patch/msgid/20230118081658.2198520-3-dmitry.baryshkov@linaro.org

Signed-off-by: Sasha Levin <sashal@kernel.org>

Signed-off-by: Jiri Slaby <jslaby@suse.cz>

---

 drivers/gpu/drm/bridge/lontium-lt9611.c | 10 ++++++++--

 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c b/drivers/gpu/drm/bridge/lontium-lt9611.c

index 2714184c..58f39b27 100644

--- a/drivers/gpu/drm/bridge/lontium-lt9611.c

+++ b/drivers/gpu/drm/bridge/lontium-lt9611.c

@@ -856,12 +856,18 @@ static enum drm_mode_status lt9611_bridge_mode_valid(struct drm_bridge *bridge,

 static void lt9611_bridge_pre_enable(struct drm_bridge *bridge)

 {

 	struct lt9611 *lt9611 = bridge_to_lt9611(bridge);

+	static const struct reg_sequence reg_cfg[] = {

+		{ 0x8102, 0x12 },

+		{ 0x8123, 0x40 },

+		{ 0x8130, 0xea },

+		{ 0x8011, 0xfa },

+	};

 	if (!lt9611->sleep)

 		return;

-	lt9611_reset(lt9611);

-	regmap_write(lt9611->regmap, 0x80ee, 0x01);

+	regmap_multi_reg_write(lt9611->regmap,

+			       reg_cfg, ARRAY_SIZE(reg_cfg));

 	lt9611->sleep = false;

 }

-- 

2.35.3