Re: [PATCH] drm/analogix_dp: Ensure the panel is properly prepared/unprepared
From: Yakir Yang
Date: Sun Jul 31 2016 - 23:40:22 EST
Sean,
On 07/30/2016 03:16 AM, Sean Paul wrote:
Instead of just preparing the panel on bind, actually prepare/unprepare
during modeset/disable. The panel must be prepared in order to read hpd
status, so we need to refcount the prepares in order to ensure we don't
accidentally turn the panel off at the wrong time.
Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
---
Hi Yakir,
This is what I was talking about upthread. I've tested it and it seems to be working.
What do you think?
Thanks for your patch, and it works. But I have introduced two
questions, and I haven't found a way to fixed them.
Sean
drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 48 +++++++++++++++++-----
1 file changed, 37 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index 32715da..7b764a4 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -960,11 +960,27 @@ enum drm_connector_status
analogix_dp_detect(struct drm_connector *connector, bool force)
{
struct analogix_dp_device *dp = to_dp(connector);
+ enum drm_connector_status status = connector_status_disconnected;
+ int ret;
- if (analogix_dp_detect_hpd(dp))
- return connector_status_disconnected;
+ if (dp->plat_data->panel && dp->dpms_mode != DRM_MODE_DPMS_ON) {
+ ret = drm_panel_prepare(dp->plat_data->panel);
+ if (ret) {
+ DRM_ERROR("failed to setup panel (%d)\n", ret);
+ return connector_status_disconnected;
+ }
+ }
+
+ if (!analogix_dp_detect_hpd(dp))
+ status = connector_status_connected;
+
+ if (dp->plat_data->panel && dp->dpms_mode != DRM_MODE_DPMS_ON) {
+ ret = drm_panel_unprepare(dp->plat_data->panel);
+ if (ret)
+ DRM_ERROR("failed to setup the panel ret = %d\n", ret);
+ }
- return connector_status_connected;
+ return status;
1. Panel would flicker at system boot time. Your patch would flash the
panel power in connector->detect() function when dp->dpms_mode isn't
DRM_MODE_DPMS_OFF. So when userspace keep detect the connector status in
boot time, we could see panel would flicker (light up for a while, and
turn off again, and keep loop for several time). I have copied some
kernel logs:
[ 11.065267] YKK --------- analogix_dp_detect:1052
[ 11.729596] YKK --------- analogix_dp_get_modes:1016
[ 11.737608] rockchip-dp ff970000.edp:
analogix_dp_read_bytes_from_dpcd: Aux Transaction fail!
[ 11.749229] rockchip-dp ff970000.edp:
analogix_dp_read_bytes_from_dpcd: Aux Transaction fail!
[ 11.760799] rockchip-dp ff970000.edp:
analogix_dp_read_bytes_from_dpcd: Aux Transaction fail!
[ 13.315962] YKK --------- analogix_dp_detect:1052
[ 13.984702] YKK --------- analogix_dp_get_modes:1016
[ 13.992977] rockchip-dp ff970000.edp:
analogix_dp_read_bytes_from_dpcd: Aux Transaction fail!
[ 14.004414] rockchip-dp ff970000.edp:
analogix_dp_read_bytes_from_dpcd: Aux Transaction fail!
[ 14.015842] rockchip-dp ff970000.edp:
analogix_dp_read_bytes_from_dpcd: Aux Transaction fail!
[ 14.183109] YKK --------- analogix_dp_bridge_pre_enable:1147
[ 14.306301] rockchip-dp ff970000.edp: Link Training Clock Recovery
success
[ 14.319130] rockchip-dp ff970000.edp: Link Training success!
[ 14.326388] rockchip-dp ff970000.edp: wait SYS_CTL_2.
[ 14.437247] rockchip-dp ff970000.edp: Timeout of video streamclk ok
[ 14.443585] rockchip-dp ff970000.edp: unable to config video
}
static void analogix_dp_connector_destroy(struct drm_connector *connector)
@@ -1035,6 +1051,18 @@ static int analogix_dp_bridge_attach(struct drm_bridge *bridge)
return 0;
}
+static void analogix_dp_bridge_pre_enable(struct drm_bridge *bridge)
+{
+ struct analogix_dp_device *dp = bridge->driver_private;
+ int ret;
+
+ if (dp->plat_data->panel) {
+ ret = drm_panel_prepare(dp->plat_data->panel);
+ if (ret)
+ DRM_ERROR("failed to setup the panel ret = %d\n", ret);
+ }
2. Driver would failed to read EDID in some case. Panel would only be
powered up in bridge->pre_enable() function which later than
connector->get_modes() function, and this would caused DPCD transfer
failed in analogix_dp_handle_edid(). This seem won't caused too big
issue, cause userspace would read EDID again after bridge/encoder is
enabled. But it's better to avoid this potential bug.
[ 11.065267] YKK --------- analogix_dp_detect:1052
[ 11.729596] YKK --------- analogix_dp_get_modes:1016
[ 11.737608] rockchip-dp ff970000.edp:
analogix_dp_read_bytes_from_dpcd: Aux Transaction fail!
[ 11.749229] rockchip-dp ff970000.edp:
analogix_dp_read_bytes_from_dpcd: Aux Transaction fail!
[ 11.760799] rockchip-dp ff970000.edp:
analogix_dp_read_bytes_from_dpcd: Aux Transaction fail!
[ 13.315962] YKK --------- analogix_dp_detect:1052
[ 13.984702] YKK --------- analogix_dp_get_modes:1016
[ 13.992977] rockchip-dp ff970000.edp:
analogix_dp_read_bytes_from_dpcd: Aux Transaction fail!
[ 14.004414] rockchip-dp ff970000.edp:
analogix_dp_read_bytes_from_dpcd: Aux Transaction fail!
[ 14.015842] rockchip-dp ff970000.edp:
analogix_dp_read_bytes_from_dpcd: Aux Transaction fail!
[ 14.183109] YKK --------- analogix_dp_bridge_pre_enable:1147
[ 14.306301] rockchip-dp ff970000.edp: Link Training Clock Recovery
success
[ 14.319130] rockchip-dp ff970000.edp: Link Training success!
[ 14.326388] rockchip-dp ff970000.edp: wait SYS_CTL_2.
[ 14.437247] rockchip-dp ff970000.edp: Timeout of video streamclk ok
[ 14.443585] rockchip-dp ff970000.edp: unable to config video
[ 14.520565] YKK --------- analogix_dp_detect:1052
[ 14.525339] YKK --------- analogix_dp_get_modes:1016
[ 14.531233] rockchip-dp ff970000.edp: EDID data does not include any
extensions.
[ 15.595724] YKK --------- analogix_dp_detect:1052
[ 15.600488] YKK --------- analogix_dp_get_modes:1016
[ 15.606451] rockchip-dp ff970000.edp: EDID data does not include any
extensions.
[ 17.327354] YKK --------- analogix_dp_detect:1052
[ 17.332105] YKK --------- analogix_dp_get_modes:1016
[ 17.338171] rockchip-dp ff970000.edp: EDID data does not include any
extensions.
[ 56.236024] YKK --------- analogix_dp_detect:1052
[ 56.240820] YKK --------- analogix_dp_get_modes:1016
[ 56.246855] rockchip-dp ff970000.edp: EDID data does not include any
extensions.
[ 64.092477] YKK --------- analogix_dp_detect:1052
[ 64.763712] YKK --------- analogix_dp_get_modes:1016
BR,
- Yakir
+}
+
static void analogix_dp_bridge_enable(struct drm_bridge *bridge)
{
struct analogix_dp_device *dp = bridge->driver_private;
@@ -1058,6 +1086,7 @@ static void analogix_dp_bridge_enable(struct drm_bridge *bridge)
static void analogix_dp_bridge_disable(struct drm_bridge *bridge)
{
struct analogix_dp_device *dp = bridge->driver_private;
+ int ret;
if (dp->dpms_mode != DRM_MODE_DPMS_ON)
return;
@@ -1077,6 +1106,10 @@ static void analogix_dp_bridge_disable(struct drm_bridge *bridge)
pm_runtime_put_sync(dp->dev);
+ ret = drm_panel_unprepare(dp->plat_data->panel);
+ if (ret)
+ DRM_ERROR("failed to setup the panel ret = %d\n", ret);
+
dp->dpms_mode = DRM_MODE_DPMS_OFF;
}
@@ -1165,9 +1198,9 @@ static void analogix_dp_bridge_nop(struct drm_bridge *bridge)
}
static const struct drm_bridge_funcs analogix_dp_bridge_funcs = {
+ .pre_enable = analogix_dp_bridge_pre_enable,
.enable = analogix_dp_bridge_enable,
.disable = analogix_dp_bridge_disable,
- .pre_enable = analogix_dp_bridge_nop,
.post_disable = analogix_dp_bridge_nop,
.mode_set = analogix_dp_bridge_mode_set,
.attach = analogix_dp_bridge_attach,
@@ -1333,13 +1366,6 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
phy_power_on(dp->phy);
- if (dp->plat_data->panel) {
- if (drm_panel_prepare(dp->plat_data->panel)) {
- DRM_ERROR("failed to setup the panel\n");
- return -EBUSY;
- }
- }
-
analogix_dp_init_dp(dp);
ret = devm_request_threaded_irq(&pdev->dev, dp->irq,