diff options
| author | Dave Airlie <airlied@redhat.com> | 2020-09-09 12:27:12 +1000 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2020-09-09 12:27:13 +1000 |
| commit | 877d8c074302c20ac0759d1a4f689c14aada420d (patch) | |
| tree | c4ac9ed42b665fc88dcc73c957cab62496037ac8 /drivers/gpu/drm/drm_dp_mst_topology.c | |
| parent | 1f4b2aca794f7aeb918ed5f0d7221d68a81d6b43 (diff) | |
| parent | 79416e97dda0118b137302575a70a14259a27d7d (diff) | |
| download | linux-877d8c074302c20ac0759d1a4f689c14aada420d.tar.bz2 | |
Merge tag 'topic/nouveau-i915-dp-helpers-and-cleanup-2020-08-31-1' of git://anongit.freedesktop.org/drm/drm-misc into drm-next
UAPI Changes:
None
Cross-subsystem Changes:
* Moves a bunch of miscellaneous DP code from the i915 driver into a set
of shared DRM DP helpers
Core Changes:
* New DRM DP helpers (see above)
Driver Changes:
* Implements usage of the aforementioned DP helpers in the nouveau
driver, along with some other various HPD related cleanup for nouveau
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/11e59ebdea7ee4f46803a21fe9b21443d2b9c401.camel@redhat.com
Diffstat (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 67dd72ea200e..17dbed0a9800 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -3487,6 +3487,28 @@ static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count) } /** + * drm_dp_read_mst_cap() - check whether or not a sink supports MST + * @aux: The DP AUX channel to use + * @dpcd: A cached copy of the DPCD capabilities for this sink + * + * Returns: %True if the sink supports MST, %false otherwise + */ +bool drm_dp_read_mst_cap(struct drm_dp_aux *aux, + const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + u8 mstm_cap; + + if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_12) + return false; + + if (drm_dp_dpcd_readb(aux, DP_MSTM_CAP, &mstm_cap) != 1) + return false; + + return mstm_cap & DP_MST_CAP; +} +EXPORT_SYMBOL(drm_dp_read_mst_cap); + +/** * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager * @mgr: manager to set state for * @mst_state: true to enable MST on this connector - false to disable. |