On Tue, Sep 14, 2021 at 05:06:41PM +0200, Maxime Ripard wrote: > Hi Sam, > > On Tue, Sep 14, 2021 at 12:41:55PM +0200, Sam Ravnborg wrote: > > On Tue, Sep 14, 2021 at 12:17:23PM +0200, Maxime Ripard wrote: > > > The drm_helper_hpd_irq_event() function is iterating over all the > > > connectors when an hotplug event is detected. > > > > > > During that iteration, it will call each connector detect function and > > > figure out if its status changed. > > > > > > Finally, if any connector changed, it will notify the user-space and the > > > clients that something changed on the DRM device. > > > > > > This is supposed to be used for drivers that don't have a hotplug > > > interrupt for individual connectors. However, drivers that can use an > > > interrupt for a single connector are left in the dust and can either > > > reimplement the logic used during the iteration for each connector or > > > use that helper and iterate over all connectors all the time. > > > > > > Since both are suboptimal, let's create a helper that will only perform > > > the status detection on a single connector. > > > > > > Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx> > > > > > > --- > > > Changes from v2: > > > - Skip connectors with DRM_CONNECTOR_POLL_HPD in drm_helper_hpd_irq_event > > > - Add drm_connector_helper_hpd_irq_event returned value documentation > > > - Improve logging > > > > > > Changes from v1: > > > - Rename the shared function > > > - Move the hotplug event notification out of the shared function > > > - Added missing locks > > > - Improve the documentation > > > - Switched to drm_dbg_kms > > > --- > > > drivers/gpu/drm/drm_probe_helper.c | 117 +++++++++++++++++++++-------- > > > include/drm/drm_probe_helper.h | 1 + > > > 2 files changed, 87 insertions(+), 31 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c > > > index 5b77fb5c1a32..a1ffc0c30b3a 100644 > > > --- a/drivers/gpu/drm/drm_probe_helper.c > > > +++ b/drivers/gpu/drm/drm_probe_helper.c > > > @@ -795,6 +795,87 @@ void drm_kms_helper_poll_fini(struct drm_device *dev) > > > } > > > EXPORT_SYMBOL(drm_kms_helper_poll_fini); > > > > > > +static bool check_connector_changed(struct drm_connector *connector) > > > +{ > > > + struct drm_device *dev = connector->dev; > > > + enum drm_connector_status old_status; > > > + u64 old_epoch_counter; > > > + bool changed = false; > > > + > > > + /* Only handle HPD capable connectors. */ > > > + drm_WARN_ON(dev, !(connector->polled & DRM_CONNECTOR_POLL_HPD)); > > > > This will WARN if DRM_CONNECTOR_POLL_HPD is not set - which the previous > > code did not. I am not sure this is intentional. > > Or have I missed something? > > Sorry, I misunderstood your previous comment and thought you wanted to > skip the !HPD connectors in the drm_helper_hpd_irq_event loop. > > What do you think would be the proper scenario here? Just return false? Re-reading the patch it looks good. I missed that the check is no longer deleted - and it is now done exactly as I thought it should be. So patch is: Reviewed-by: Sam Ravnborg <sam@xxxxxxxxxxxx> Sam