On Fri, May 30, 2025 at 05:54:31PM +0800, Yongbang Shi wrote:
From: Baihan Li <libai...@huawei.com>
In early OS versions， there is a bug in hibmc-drm driver previously,
Which OS? What does that mean? Why do we need to workaround userspace
issues in the kernel?
We use OpenEuler 22.03, there is a VGA cfg(video=VGA-1:640x480-32@60me) in GRUB
args.
If it exists, it will affect DP HPD.
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;
You are again trying to tie VGA and DP status, so NAK.
+}
+
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
