From: Baihan Li <libai...@huawei.com>

In early OS versions, there is a bug in hibmc-drm driver previously,
so some OS add a VGA parameter in GRUB(video=VGA-1:640x480-32@60me) to
fix the bug, that will config a force VGA mode to drm driver. However, the
HPD problem exists that mentioned in previous patch, so change VGA's status
in force() to compatible with some older OS versions.

Fixes: f9698f802e50 ("drm/hisilicon/hibmc: Restructuring the header dp_reg.h")
Signed-off-by: Baihan Li <libai...@huawei.com>
---
 drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c 
b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c
index 73dd3d5fc26c..d609ccda2f2a 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c
@@ -61,6 +61,19 @@ static int hibmc_vdac_detect(struct drm_connector 
*connector, struct drm_modeset
        return connector_status_connected;
 }
 
+static void hibmc_vdac_force(struct drm_connector *connector)
+{
+       struct hibmc_drm_private *priv = to_hibmc_drm_private(connector->dev);
+       struct hibmc_dp *dp = &priv->dp;
+
+       if (dp->hpd_status) {
+               connector->status = connector_status_disconnected;
+               return;
+       }
+
+       connector->status = connector_status_connected;
+}
+
 static void hibmc_connector_destroy(struct drm_connector *connector)
 {
        struct hibmc_vdac *vdac = to_hibmc_vdac(connector);
@@ -81,6 +94,7 @@ static const struct drm_connector_funcs hibmc_connector_funcs 
= {
        .reset = drm_atomic_helper_connector_reset,
        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+       .force = hibmc_vdac_force,
 };
 
 static void hibmc_encoder_mode_set(struct drm_encoder *encoder,
-- 
2.33.0

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