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@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>

diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c b/drivers/gpu/drm/bridge/lontium-lt9611.c
index 2714184cc53f4332c4dc750f2205f405edad8c47..58f39b279217948f23fb211542d60cd7af7ce3e5 100644 (file)
--- 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;
 }