Patch "drm/bridge: lt9611: fix HPD reenablement" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/bridge: lt9611: fix HPD reenablement

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-bridge-lt9611-fix-hpd-reenablement.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit b93e177c7c9c5480575ed744e2410ca7d33f7729
Author: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Date:   Wed Jan 18 10:16:47 2023 +0200

    drm/bridge: lt9611: fix HPD reenablement
    
    [ 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@xxxxxxxxxx>
    Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
    Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
    Link: https://patchwork.freedesktop.org/patch/msgid/20230118081658.2198520-3-dmitry.baryshkov@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c b/drivers/gpu/drm/bridge/lontium-lt9611.c
index 2714184cc53f4..58f39b2792179 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;
 }