On Fri, 11 Oct 2024, Thomas Zimmermann <tzimmermann@xxxxxxx> wrote:
> Add the bmc_attached flag to struct drm_connector to signal the
> presence of a virtual BMC output. The connector reports to be in
> status connected even without a physically connected display. Fbcon
> or userspace compositors would otherwise stop displaying to the
> BMC.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> ---
> drivers/gpu/drm/drm_probe_helper.c | 6 +++++-
> include/drm/drm_connector.h | 8 ++++++++
> 2 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
> index df44be128e72..83c3f2d42d49 100644
> --- a/drivers/gpu/drm/drm_probe_helper.c
> +++ b/drivers/gpu/drm/drm_probe_helper.c
> @@ -605,7 +605,11 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
> ret = connector_status_unknown;
>
> connector->physical_status = ret;
> - connector->status = connector->physical_status;
> +
> + if (connector->bmc_attached)
> + connector->status = connector_status_connected;
> + else
> + connector->status = connector->physical_status;
Perhaps all this would make more sense squashed into the previous patch?
> }
>
> /*
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 37e951f04ae8..ed360ae35f21 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -1802,6 +1802,14 @@ struct drm_connector {
> */
> bool ycbcr_420_allowed;
>
> + /**
> + * @ bmc_attached:
> + * The connector has a BMC transparently attached to it. It has to
> + * report a connected status, even without a physically connected
> + * display.
> + */
> + bool bmc_attached;
Who is supposed to set this and when? Can it be changed during connector
life cycle? (I find myself wishing for C++ public/private members,
*gasp*!)
Again, there's bound to be people for whom "BMC" means nothing, and
therefore this member means nothing. I'm wondering if the name could be
something with a higher level of abstraction. In some ways, this is
related to or a special case of connector->force, but without the
uapi. You know, "logical force", with the use case being BMC.
BR,
Jani.
> +
> /**
> * @registration_state: Is this connector initializing, exposed
> * (registered) with userspace, or unregistered?
--
Jani Nikula, Intel
