[PATCH v4 drm-dp 08/11] drm/hisilicon/hibmc: fix no showing when no connectors connected
Yongbang Shi
shiyongbang at huawei.com
Wed Aug 13 09:42:35 UTC 2025
From: Baihan Li <libaihan at huawei.com>
Our chip support KVM over IP feature, so hibmc driver need to support
displaying without any connectors plugged in. If no connectors connected,
set the vdac connector status to 'connected' to handle BMC KVM. Use
is_connected to check all physical outputs.
For get_modes: using BMC modes for connector if no display is attached to
phys VGA cable, otherwise use EDID modes by drm_connector_helper_get_modes,
because KVM doesn't provide EDID reads.
Fixes: 4c962bc929f1 ("drm/hisilicon/hibmc: Add vga connector detect functions")
Signed-off-by: Baihan Li <libaihan at huawei.com>
Signed-off-by: Yongbang Shi <shiyongbang at huawei.com>
---
ChangeLog:
v3 -> v4:
- add KVM edid in commit message, suggested by Dmitry Baryshkov.
- fix magic values, suggested by Dmitry Baryshkov.
v2 -> v3:
- fix hibmc_connector_get_modes() and hibmc_vdac_detect() to realize BMC KVM, suggested by Dmitry Baryshkov.
---
.../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c | 20 ++++--
.../gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 2 +
.../gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h | 7 +++
.../gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c | 62 +++++++++++++------
4 files changed, 68 insertions(+), 23 deletions(-)
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
index 5cac04b7d4a4..9626c60a9115 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
@@ -35,12 +35,22 @@ static int hibmc_dp_connector_get_modes(struct drm_connector *connector)
static int hibmc_dp_detect(struct drm_connector *connector,
struct drm_modeset_acquire_ctx *ctx, bool force)
{
- struct hibmc_dp *dp = to_hibmc_dp(connector);
+ struct hibmc_drm_private *priv = to_hibmc_drm_private(connector->dev);
+ int ret;
+
+ mutex_lock(&priv->connect_lock);
+
+ if (priv->dp.hpd_status) {
+ priv->connect_status_map |= HIBMC_DP_STATUS;
+ ret = connector_status_connected;
+ } else {
+ priv->connect_status_map &= ~HIBMC_DP_STATUS;
+ ret = connector_status_disconnected;
+ }
- if (dp->hpd_status)
- return connector_status_connected;
- else
- return connector_status_disconnected;
+ mutex_unlock(&priv->connect_lock);
+
+ return ret;
}
static int hibmc_dp_mode_valid(struct drm_connector *connector,
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
index 289304500ab0..bdf14ad52cd3 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
@@ -162,6 +162,8 @@ static int hibmc_kms_init(struct hibmc_drm_private *priv)
drm_for_each_encoder(encoder, dev)
encoder->possible_clones = clone_mask;
+ mutex_init(&priv->connect_lock);
+
return 0;
}
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
index ca8502e2760c..4eee33fbc1f4 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
@@ -24,6 +24,8 @@
#define HIBMC_MIN_VECTORS 1
#define HIBMC_MAX_VECTORS 2
+#define HIBMC_DP_STATUS BIT(0)
+#define HIBMC_VGA_STATUS BIT(1)
struct hibmc_vdac {
struct drm_device *dev;
@@ -31,6 +33,7 @@ struct hibmc_vdac {
struct drm_connector connector;
struct i2c_adapter adapter;
struct i2c_algo_bit_data bit_data;
+ int phys_status;
};
struct hibmc_drm_private {
@@ -43,6 +46,10 @@ struct hibmc_drm_private {
struct drm_crtc crtc;
struct hibmc_vdac vdac;
struct hibmc_dp dp;
+
+ /* VGA and DP phys connect status, BIT(0) is DP, BIT(1) is VGA */
+ u32 connect_status_map;
+ struct mutex connect_lock; /* protect connect_status_map value */
};
static inline struct hibmc_vdac *to_hibmc_vdac(struct drm_connector *connector)
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c
index 841e81f47b68..922c0810723d 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c
@@ -25,27 +25,18 @@
static int hibmc_connector_get_modes(struct drm_connector *connector)
{
struct hibmc_vdac *vdac = to_hibmc_vdac(connector);
- const struct drm_edid *drm_edid;
int count;
- drm_edid = drm_edid_read_ddc(connector, &vdac->adapter);
-
- drm_edid_connector_update(connector, drm_edid);
-
- if (drm_edid) {
- count = drm_edid_connector_add_modes(connector);
- if (count)
- goto out;
+ if (vdac->phys_status == connector_status_connected) {
+ count = drm_connector_helper_get_modes(connector);
+ } else {
+ drm_edid_connector_update(connector, NULL);
+ count = drm_add_modes_noedid(connector,
+ connector->dev->mode_config.max_width,
+ connector->dev->mode_config.max_height);
+ drm_set_preferred_mode(connector, 1024, 768);
}
- count = drm_add_modes_noedid(connector,
- connector->dev->mode_config.max_width,
- connector->dev->mode_config.max_height);
- drm_set_preferred_mode(connector, 1024, 768);
-
-out:
- drm_edid_free(drm_edid);
-
return count;
}
@@ -57,10 +48,45 @@ static void hibmc_connector_destroy(struct drm_connector *connector)
drm_connector_cleanup(connector);
}
+static int hibmc_vdac_detect(struct drm_connector *connector,
+ struct drm_modeset_acquire_ctx *ctx,
+ bool force)
+{
+ struct hibmc_drm_private *priv = to_hibmc_drm_private(connector->dev);
+ struct hibmc_vdac *vdac = to_hibmc_vdac(connector);
+ int ret = connector_status_disconnected;
+ int status;
+
+ status = drm_connector_helper_detect_from_ddc(connector, ctx, force);
+
+ vdac->phys_status = status;
+
+ mutex_lock(&priv->connect_lock);
+
+ if (status == connector_status_connected) {
+ priv->connect_status_map |= HIBMC_VGA_STATUS;
+ ret = connector_status_connected;
+ goto exit;
+ }
+
+ priv->connect_status_map &= ~HIBMC_VGA_STATUS;
+
+ /* if all connectors are disconnected,
+ * return connected to support BMC KVM display.
+ */
+ if (!priv->connect_status_map)
+ ret = connector_status_connected;
+
+exit:
+ mutex_unlock(&priv->connect_lock);
+
+ return ret;
+}
+
static const struct drm_connector_helper_funcs
hibmc_connector_helper_funcs = {
.get_modes = hibmc_connector_get_modes,
- .detect_ctx = drm_connector_helper_detect_from_ddc,
+ .detect_ctx = hibmc_vdac_detect,
};
static const struct drm_connector_funcs hibmc_connector_funcs = {
--
2.33.0
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