Re: [PATCH RESEND v3 1/6] drm/connector: report IRQ_HPD events to drm_connector_oob_hotplug_event()

[Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>]

On Thu, May 21, 2026 at 09:47:29AM +0200, Maxime Ripard wrote:
> On Wed, May 13, 2026 at 09:23:21PM +0300, Dmitry Baryshkov wrote:
> > The DisplayPort standard defines a special kind of events called IRQ.
> > These events are used to notify DP Source about the events on the Sink
> > side. It is extremely important for DP MST handling, where the MST
> > events are reported through this IRQ.
> > 
> > In case of the USB-C DP AltMode there is no actual HPD pulse, but the
> > events are ported through the bits in the AltMode VDOs.
> > 
> > Extend the drm_connector_oob_hotplug_event() interface and report IRQ
> > events to the DisplayPort Sink drivers.
> > 
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> > ---
> >  drivers/gpu/drm/drm_connector.c          |  5 ++++-
> >  drivers/usb/typec/altmodes/displayport.c | 15 +++++++++++----
> >  include/drm/drm_connector.h              | 19 ++++++++++++++++++-
> >  3 files changed, 33 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > index 47dc53c4a738..edee9daccd51 100644
> > --- a/drivers/gpu/drm/drm_connector.c
> > +++ b/drivers/gpu/drm/drm_connector.c
> > @@ -3510,6 +3510,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >   * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
> >   * @connector_fwnode: fwnode_handle to report the event on
> >   * @status: hot plug detect logical state
> > + * @extra_status: additional information provided by the sink without changing
> > + * the HPD state (or in addition to such a change).
> >   *
> >   * On some hardware a hotplug event notification may come from outside the display
> >   * driver / device. An example of this is some USB Type-C setups where the hardware
> > @@ -3520,7 +3522,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >   * a drm_connector reference through calling drm_connector_find_by_fwnode().
> >   */
> >  void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> > -				     enum drm_connector_status status)
> > +				     enum drm_connector_status status,
> > +				     enum drm_connector_status_extra extra_status)
> >  {
> >  	struct drm_connector *connector;
> >  
> > diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> > index 35d9c3086990..7182a8e2e710 100644
> > --- a/drivers/usb/typec/altmodes/displayport.c
> > +++ b/drivers/usb/typec/altmodes/displayport.c
> > @@ -189,7 +189,9 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
> >  	} else {
> >  		drm_connector_oob_hotplug_event(dp->connector_fwnode,
> >  						hpd ? connector_status_connected :
> > -						      connector_status_disconnected);
> > +						      connector_status_disconnected,
> > +						(hpd && irq_hpd) ? DRM_CONNECTOR_DP_IRQ_HPD :
> > +								   DRM_CONNECTOR_NO_EXTRA_STATUS);
> 
> Since the extra status itself, and what the options mean, are DP specific, do we really want to
> extend drm_connector_oob_hotplug_event()? I think I'd prefer to have a DP specific variant, with its
> own set of parameters.

I can try arguing that drm_connector_oob_hotplug_event() is DP-specific,
there are no other users for it, only the DP AltMode driver.

Anyway, do you just mean new API here or new API and a new connector
callback?

-- 
With best wishes
Dmitry

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