Messages in this thread | | | Subject | Re: [PATCH] drm/probe_helper: Don't bother probing when connectors are forced off | From | Lyude Paul <> | Date | Mon, 17 Sep 2018 17:12:04 -0400 |
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On Mon, 2018-09-17 at 21:16 +0300, Ville Syrjälä wrote: > On Mon, Sep 17, 2018 at 02:10:02PM -0400, Lyude Paul wrote: > > On Mon, 2018-09-17 at 20:55 +0300, Ville Syrjälä wrote: > > > On Mon, Sep 17, 2018 at 01:43:44PM -0400, Lyude Paul wrote: > > > > Userspace asked them to be forced off, so why would we care about what a > > > > probe tells us? > > > > > > I believe there should be force checks in the callers already. > > > Or are we missing some? > > > > JFYI, what triggered me to send this patch are these error messages that > > come > > from nouveau when a hotplug happens on a port that we've forced off: > > > > [ 1903.918104] nouveau 0000:01:00.0: DRM: DDC responded, but no EDID for DP- > > 2 > > [ 1903.918123] [drm:drm_helper_hpd_irq_event [drm_kms_helper]] > > [CONNECTOR:61:DP-2] status updated from disconnected to disconnected > > > > That being said; I'm sure there are probably some checks missing, but I > > don't > > really see the purpose in calling the driver's probe functions at all if > > they're > > just supposed to return the status we forced. > > Digging through my cobweb ridden local git repository I found this: > > commit bbd17813a7c7d0210c619365707044d0fb29e3f0 > Author: Ville Syrjälä <ville.syrjala@linux.intel.com> > Date: Mon Jun 10 15:28:55 2013 +0300 > > drm: Ignore forced connectors in drm_helper_hpd_irq_event() > > drm_helper_hpd_irq_event() calls the connector's .detect() function > even for forced connectors. If the returned status doesn't match the > forced status, we will send the hotplug event, causing userspace to > re-probe all the connectors. Eventually we should end up back where > we started when drm_helper_probe_single_connector_modes() overwrites > the connector status with the forced status. > > We can avoid all that pointles work if we just skip forced connectors > in drm_helper_hpd_irq_event(). > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > > diff --git a/drivers/gpu/drm/drm_crtc_helper.c > b/drivers/gpu/drm/drm_crtc_helper.c > index ed1334e27c33..4fc2ad76c107 100644 > --- a/drivers/gpu/drm/drm_crtc_helper.c > +++ b/drivers/gpu/drm/drm_crtc_helper.c > @@ -1086,6 +1086,10 @@ void drm_helper_hpd_irq_event(struct drm_device *dev) > mutex_lock(&dev->mode_config.mutex); > list_for_each_entry(connector, &dev->mode_config.connector_list, head) { > > + /* Ignore forced connectors. */ > + if (connector->force) > + continue; > + > /* Only handle HPD capable connectors. */ > if (!(connector->polled & DRM_CONNECTOR_POLL_HPD)) > continue; > > > I guess I never sent it out.
Ahhh, to be honest though this patch isn't really enough. drm_helper_hpd_irq_event() isn't going to be used by all drivers (I may remove some usage of it in nouveau in the near future, even) so I still think it would be a better idea to just add this into drm_helper_probe_detect() and drm_helper_probe_detect_ctx() so everything gets covered
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