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?
> 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
>
--
With best wishes
Dmitry
