| Message ID | 20220602201757.30431-2-lyude@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Misc drive-by fixes for MST helpers | expand |
[Public] Thanks, Lyude. Feel free to add Reviewed-by: Wayne Lin <Wayne.Lin@amd.com> > -----Original Message----- > From: Lyude Paul <lyude@redhat.com> > Sent: Friday, June 3, 2022 4:18 AM > To: dri-devel@lists.freedesktop.org > Cc: David Airlie <airlied@linux.ie>; Daniel Vetter <daniel@ffwll.ch>; Thomas > Zimmermann <tzimmermann@suse.de>; Lin, Wayne > <Wayne.Lin@amd.com>; Jani Nikula <jani.nikula@intel.com>; Lakha, > Bhawanpreet <Bhawanpreet.Lakha@amd.com>; Rajkumar Subbiah > <rsubbia@codeaurora.org>; open list <linux-kernel@vger.kernel.org> > Subject: [PATCH 1/3] drm/display/dp_mst: Don't validate port refs in > drm_dp_check_and_send_link_address() > > Drive-by cleanup, we don't need to validate the port references here as we > already previously went through the effort of refactoring things such that > we're guaranteed to be able to access ->mstb and ->port safely from > drm_dp_check_and_send_link_address(), since the only two places in the > codebase that drop an MST reference in such a way that it would remove it > from the topology are both protected under probe_lock. > > Thanks for that, past Lyude! > > Signed-off-by: Lyude Paul <lyude@redhat.com> > --- > drivers/gpu/drm/display/drm_dp_mst_topology.c | 22 +++++-------------- > 1 file changed, 6 insertions(+), 16 deletions(-) > > diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c > b/drivers/gpu/drm/display/drm_dp_mst_topology.c > index 67b3b9697da7..d84673b3294b 100644 > --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c > +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c > @@ -2666,24 +2666,14 @@ static int > drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr > *mg > } > > list_for_each_entry(port, &mstb->ports, next) { > - struct drm_dp_mst_branch *mstb_child = NULL; > - > - if (port->input || !port->ddps) > + if (port->input || !port->ddps || !port->mstb) > continue; > > - if (port->mstb) > - mstb_child = > drm_dp_mst_topology_get_mstb_validated( > - mgr, port->mstb); > - > - if (mstb_child) { > - ret = drm_dp_check_and_send_link_address(mgr, > - mstb_child); > - drm_dp_mst_topology_put_mstb(mstb_child); > - if (ret == 1) > - changed = true; > - else if (ret < 0) > - return ret; > - } > + ret = drm_dp_check_and_send_link_address(mgr, port- > >mstb); > + if (ret == 1) > + changed = true; > + else if (ret < 0) > + return ret; > } > > return changed; > -- > 2.35.3 -- Regards, Wayne
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index 67b3b9697da7..d84673b3294b 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -2666,24 +2666,14 @@ static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mg } list_for_each_entry(port, &mstb->ports, next) { - struct drm_dp_mst_branch *mstb_child = NULL; - - if (port->input || !port->ddps) + if (port->input || !port->ddps || !port->mstb) continue; - if (port->mstb) - mstb_child = drm_dp_mst_topology_get_mstb_validated( - mgr, port->mstb); - - if (mstb_child) { - ret = drm_dp_check_and_send_link_address(mgr, - mstb_child); - drm_dp_mst_topology_put_mstb(mstb_child); - if (ret == 1) - changed = true; - else if (ret < 0) - return ret; - } + ret = drm_dp_check_and_send_link_address(mgr, port->mstb); + if (ret == 1) + changed = true; + else if (ret < 0) + return ret; } return changed;
Drive-by cleanup, we don't need to validate the port references here as we already previously went through the effort of refactoring things such that we're guaranteed to be able to access ->mstb and ->port safely from drm_dp_check_and_send_link_address(), since the only two places in the codebase that drop an MST reference in such a way that it would remove it from the topology are both protected under probe_lock. Thanks for that, past Lyude! Signed-off-by: Lyude Paul <lyude@redhat.com> --- drivers/gpu/drm/display/drm_dp_mst_topology.c | 22 +++++-------------- 1 file changed, 6 insertions(+), 16 deletions(-)