diff options
| author | Imre Deak <imre.deak@intel.com> | 2021-02-16 15:34:48 +0300 |
|---|---|---|
| committer | Imre Deak <imre.deak@intel.com> | 2021-02-18 17:41:35 +0300 |
| commit | f0297cc0fd2bded129ccc1e00528d06362b6075d (patch) | |
| tree | e82977f7f8b158b48539c4eec2bbc0748de2ed66 /drivers/gpu | |
| parent | 1b588c82f63ebef55bccac4f0ca9c2825b9a9ae4 (diff) | |
| download | linux-f0297cc0fd2bded129ccc1e00528d06362b6075d.tar.xz | |
drm/dp_mst: Tune down the WARN modesetting a port with full_pbn=0
It's possible to modeset a connector/mst port that has a 0 full_pbn
value: if the sink on the port deasserts its HPD and a branch device
reports this via a CSN with the port's ddps=0 and pdt!=NONE the driver
clears full_pbn, but the corresponding connector can be still
modesetted.
This happened on a DELL U2719D monitor as the branch device and an LG
27UL650-W daisy-chained to it, the LG monitor generating a long HPD
pulse (doing this for some reason always when waking up from some power
saving state).
Tune down the WARN about this scenario to a debug message.
v2: Use the correct atomic debug message level. (Lyude)
References: https://gitlab.freedesktop.org/drm/intel/-/issues/1917
Cc: Lyude Paul <lyude@redhat.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210216123448.410545-1-imre.deak@intel.com
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 2fb84e7f1e69..6dba74416841 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -5105,11 +5105,16 @@ drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, if (!found) return 0; - /* This should never happen, as it means we tried to - * set a mode before querying the full_pbn + /* + * This could happen if the sink deasserted its HPD line, but + * the branch device still reports it as attached (PDT != NONE). */ - if (WARN_ON(!port->full_pbn)) + if (!port->full_pbn) { + drm_dbg_atomic(port->mgr->dev, + "[MSTB:%p] [MST PORT:%p] no BW available for the port\n", + port->parent, port); return -EINVAL; + } pbn_used = vcpi->pbn; } else { |