RE: [PATCH v2] drm/bridge: it6505: Power on downstream device in .atomic_enable

From: allen.chen
Date: Thu Jul 14 2022 - 06:42:04 EST

Reviewed-by: Allen Chen <allen.chen@xxxxxxxxxx>

-----Original Message-----
From: Pin-Yen Lin <treapking@xxxxxxxxxxxx>
Sent: Thursday, July 14, 2022 5:39 PM
To: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>; Neil Armstrong <narmstrong@xxxxxxxxxxxx>; Robert Foss <robert.foss@xxxxxxxxxx>; Laurent Pinchart <Laurent.pinchart@xxxxxxxxxxxxxxxx>; Jonas Karlman <jonas@xxxxxxxxx>; Jernej Skrabec <jernej.skrabec@xxxxxxxxx>; David Airlie <airlied@xxxxxxxx>; Daniel Vetter <daniel@xxxxxxxx>
Cc: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>; Allen Chen (陳柏宇) <allen.chen@xxxxxxxxxx>; Pin-Yen Lin <treapking@xxxxxxxxxxxx>; dri-devel@xxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: [PATCH v2] drm/bridge: it6505: Power on downstream device in .atomic_enable

Send DPCD DP_SET_POWER_D0 command to the monitor in .atomic_enable callback. Without this command, some monitors won't show up again after changing the resolution.

Fixes: 46ca7da7f1e8 ("drm/bridge: it6505: Send DPCD SET_POWER to downstream")

Signed-off-by: Pin-Yen Lin <treapking@xxxxxxxxxxxx>

Changes in v2:
- Update the typo in the summary (power on --> power off)
- Re-write the commit message to make it clearer.

drivers/gpu/drm/bridge/ite-it6505.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 4b673c4792d7..e5626035f311 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -2945,6 +2945,9 @@ static void it6505_bridge_atomic_enable(struct drm_bridge *bridge,
if (ret)
dev_err(dev, "Failed to setup AVI infoframe: %d", ret);

+ it6505_drm_dp_link_set_power(&it6505->aux, &it6505->link,
it6505_update_video_parameter(it6505, mode);

ret = it6505_send_video_infoframe(it6505, &frame);