On Wed, Oct 26, 2016 at 12:05:54PM +0300, ville.syrjala@xxxxxxxxxxxxxxx wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > The i2c adapter is only relevant for some peer device types, so > let's clear the pdt if it's still the same as the old_pdt when we > tear down the i2c adapter. > > I don't really like this design pattern of updating port->whatever > before doing the accompanying changes and passing around old_whatever > to figure stuff out. Would make much more sense to me to the pass the > new value around and only update the port->whatever when things are > consistent. But let's try to work with what we have right now. > > Cc: stable@xxxxxxxxxxxxxxx > Cc: Carlos Santa <carlos.santa@xxxxxxxxx> > Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> > Tested-by: Carlos Santa <carlos.santa@xxxxxxxxx> > Tested-by: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97666 > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > --- > drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c > index 04e457117980..956babc161e5 100644 > --- a/drivers/gpu/drm/drm_dp_mst_topology.c > +++ b/drivers/gpu/drm/drm_dp_mst_topology.c > @@ -882,6 +882,9 @@ static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt) > drm_dp_put_mst_branch_device(mstb); > break; > } > + > + if (port->pdt == old_pdt) > + port->pdt = DP_PEER_DEVICE_NONE; So from my understanding this is needed for the callsite in drm_dp_destroy_connector_work(). All others are either the final destroy path, or set up the ->pdt to something before calling this function. Only this call site passes port->pdt. I think we should instead change this callsite to set the port->pdt to NONE after the call, i.e. diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 04e457117980..36f47092c703 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -2919,6 +2919,7 @@ static void drm_dp_destroy_connector_work(struct work_struct *work) mgr->cbs->destroy_connector(mgr, port->connector); drm_dp_port_teardown_pdt(port, port->pdt); + port->pdt = DP_PEER_DEVICE_NONE; if (!port->input && port->vcpi.vcpi > 0) { drm_dp_mst_reset_vcpi_slots(mgr, port); I think that would be more consistent than spreading the control flow even more like in your patch. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html