[PATCH 5.18 378/879] drm/bridge: it6505: Send DPCD SET_POWER to downstream

Greg Kroah-Hartman
2022-06-08T00:15:19Z

From: Pin-Yen Lin <treapking@chromium.org>

[ Upstream commit 46ca7da7f1e8592af6059419176dd58c10dcdb5b ]

Send DPCD SET_POWER command to downstream in .atomic_disable to make the
downstream monitor enter the power down mode, so the device suspend won't
be affected.

Fixes: b5c84a9edcd418 ("drm/bridge: add it6505 driver")
Signed-off-by: Pin-Yen Lin <treapking@chromium.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220425134424.1150965-1-treapking@chromium.org
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/bridge/ite-it6505.c | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index f2f101220ade..c54664677172 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -737,8 +737,9 @@ static int it6505_drm_dp_link_probe(struct drm_dp_aux *aux,
return 0;
}

-static int it6505_drm_dp_link_power_up(struct drm_dp_aux *aux,
- struct it6505_drm_dp_link *link)
+static int it6505_drm_dp_link_set_power(struct drm_dp_aux *aux,
+ struct it6505_drm_dp_link *link,
+ u8 mode)
{
u8 value;
int err;
@@ -752,18 +753,20 @@ static int it6505_drm_dp_link_power_up(struct drm_dp_aux *aux,
return err;

value &= ~DP_SET_POWER_MASK;
- value |= DP_SET_POWER_D0;
+ value |= mode;

err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
if (err < 0)
return err;

- /*
- * According to the DP 1.1 specification, a "Sink Device must exit the
- * power saving state within 1 ms" (Section 2.5.3.1, Table 5-52, "Sink
- * Control Field" (register 0x600).
- */
- usleep_range(1000, 2000);
+ if (mode == DP_SET_POWER_D0) {
+ /*
+ * According to the DP 1.1 specification, a "Sink Device must
+ * exit the power saving state within 1 ms" (Section 2.5.3.1,
+ * Table 5-52, "Sink Control Field" (register 0x600).
+ */
+ usleep_range(1000, 2000);
+ }

return 0;
}
@@ -2624,7 +2627,8 @@ static enum drm_connector_status it6505_detect(struct it6505 *it6505)
if (it6505_get_sink_hpd_status(it6505)) {
it6505_aux_on(it6505);
it6505_drm_dp_link_probe(&it6505->aux, &it6505->link);
- it6505_drm_dp_link_power_up(&it6505->aux, &it6505->link);
+ it6505_drm_dp_link_set_power(&it6505->aux, &it6505->link,
+ DP_SET_POWER_D0);
it6505->auto_train_retry = AUTO_TRAIN_RETRY;

if (it6505->dpcd[0] == 0) {
@@ -2960,8 +2964,11 @@ static void it6505_bridge_atomic_disable(struct drm_bridge *bridge,

DRM_DEV_DEBUG_DRIVER(dev, "start");

- if (it6505->powered)
+ if (it6505->powered) {
it6505_video_disable(it6505);
+ it6505_drm_dp_link_set_power(&it6505->aux, &it6505->link,
+ DP_SET_POWER_D3);
+ }
}

static enum drm_connector_status
--
2.35.1