diff options
| author | Lyude Paul <lyude@redhat.com> | 2020-08-26 14:24:45 -0400 |
|---|---|---|
| committer | Lyude Paul <lyude@redhat.com> | 2020-08-31 19:10:08 -0400 |
| commit | 4b4659128e634ce65dc02acf297d623f5bc97497 (patch) | |
| tree | f21b5cec4671680c3cbe554b7db4c73b73131a08 /drivers/gpu/drm/drm_dp_mst_topology.c | |
| parent | a0922278f83eae085fdf73d06f71bbdfb9d6789e (diff) | |
| download | linux-4b4659128e634ce65dc02acf297d623f5bc97497.tar.bz2 | |
drm/i915/dp: Extract drm_dp_read_mst_cap()
Just a tiny drive-by cleanup, we can consolidate i915's code for
checking for MST support into a helper to be shared across drivers.
v5:
* Drop !!()
* Move drm_dp_has_mst() out of header
* Change name from drm_dp_has_mst() to drm_dp_read_mst_cap()
Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Sean Paul <sean@poorly.run>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200826182456.322681-10-lyude@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 b23cb2fec3f3..61755c26fac0 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. |