This patch got obsoleted and cc'd by accident, feel free to ignore On Fri, 2019-01-11 at 14:01 +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote: > The patch below does not apply to the 4.20-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to <stable@xxxxxxxxxxxxxxx>. > > thanks, > > greg k-h > > ------------------ original commit in Linus's tree ------------------ > > From 4d80273976bf880c4bed9359b8f2d45663140c86 Mon Sep 17 00:00:00 2001 > From: Lyude Paul <lyude@xxxxxxxxxx> > Date: Mon, 8 Oct 2018 19:24:30 -0400 > Subject: [PATCH] drm/atomic_helper: Disallow new modesets on unregistered > connectors > > With the exception of modesets which would switch the DPMS state of a > connector from on to off, we want to make sure that we disallow all > modesets which would result in enabling a new monitor or a new mode > configuration on a monitor if the connector for the display in question > is no longer registered. This allows us to stop userspace from trying to > enable new displays on connectors for an MST topology that were just > removed from the system, without preventing userspace from disabling > DPMS on those connectors. > > Changes since v5: > - Fix typo in comment, nothing else > > Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx> > Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Link: > https://patchwork.freedesktop.org/patch/msgid/20181008232437.5571-2-lyude@xxxxxxxxxx > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c > b/drivers/gpu/drm/drm_atomic_helper.c > index 3cf1aa132778..c1a35078b2b9 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -308,6 +308,26 @@ update_connector_routing(struct drm_atomic_state > *state, > return 0; > } > > + crtc_state = drm_atomic_get_new_crtc_state(state, > + new_connector_state->crtc); > + /* > + * For compatibility with legacy users, we want to make sure that > + * we allow DPMS On->Off modesets on unregistered connectors. Modesets > + * which would result in anything else must be considered invalid, to > + * avoid turning on new displays on dead connectors. > + * > + * Since the connector can be unregistered at any point during an > + * atomic check or commit, this is racy. But that's OK: all we care > + * about is ensuring that userspace can't do anything but shut off the > + * display on a connector that was destroyed after its been notified, > + * not before. > + */ > + if (!READ_ONCE(connector->registered) && crtc_state->active) { > + DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] is not registered\n", > + connector->base.id, connector->name); > + return -EINVAL; > + } > + > funcs = connector->helper_private; > > if (funcs->atomic_best_encoder) > @@ -352,7 +372,6 @@ update_connector_routing(struct drm_atomic_state *state, > > set_best_encoder(state, new_connector_state, new_encoder); > > - crtc_state = drm_atomic_get_new_crtc_state(state, new_connector_state- > >crtc); > crtc_state->connectors_changed = true; > > DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] using [ENCODER:%d:%s] on > [CRTC:%d:%s]\n", > -- Cheers, Lyude Paul
