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@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
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.
--
Ville Syrjälä
Intel
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