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| author | Dave Airlie <airlied@redhat.com> | 2021-02-04 03:57:18 +0100 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2021-02-04 03:57:28 +0100 |
| commit | ce7c3bded64abbaabb1146803d0ce09694dc95e0 (patch) | |
| tree | ce73ca923f17d16bdae736fd445c309936e9d123 /drivers/gpu/drm/drm_dp_mst_topology.c | |
| parent | Merge tag 'drm/tegra/for-5.12-rc1' of ssh://git.freedesktop.org/git/tegra/lin... (diff) | |
| parent | drm/i915/dp: Prevent setting the LTTPR LT mode if no LTTPRs are detected (diff) | |
| download | linux-ce7c3bded64abbaabb1146803d0ce09694dc95e0.tar.xz linux-ce7c3bded64abbaabb1146803d0ce09694dc95e0.zip | |
Merge tag 'drm-intel-next-2021-01-29' of git://anongit.freedesktop.org/drm/drm-intel into drm-next
- WARN if plane src coords are too big (Ville)
- Prevent double YUV range correction on HDR planes (Andres)
- DP MST related Fixes (Sean, Imre)
- More clean-up around DRAM detection code (Jose)
- Actually async flips enable for all ilk+ platforms (Ville)
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210129225328.GA1041349@intel.com
Diffstat (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 475939138b21..e82b596d646c 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -3629,14 +3629,26 @@ static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr, return 0; } -static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count) +/** + * drm_dp_get_vc_payload_bw - get the VC payload BW for an MST link + * @link_rate: link rate in 10kbits/s units + * @link_lane_count: lane count + * + * Calculate the total bandwidth of a MultiStream Transport link. The returned + * value is in units of PBNs/(timeslots/1 MTP). This value can be used to + * convert the number of PBNs required for a given stream to the number of + * timeslots this stream requires in each MTP. + */ +int drm_dp_get_vc_payload_bw(int link_rate, int link_lane_count) { - if (dp_link_bw == 0 || dp_link_count == 0) - DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n", - dp_link_bw, dp_link_count); + if (link_rate == 0 || link_lane_count == 0) + DRM_DEBUG_KMS("invalid link rate/lane count: (%d / %d)\n", + link_rate, link_lane_count); - return dp_link_bw * dp_link_count / 2; + /* See DP v2.0 2.6.4.2, VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */ + return link_rate * link_lane_count / 54000; } +EXPORT_SYMBOL(drm_dp_get_vc_payload_bw); /** * drm_dp_read_mst_cap() - check whether or not a sink supports MST @@ -3692,7 +3704,7 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms goto out_unlock; } - mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1], + mgr->pbn_div = drm_dp_get_vc_payload_bw(drm_dp_bw_code_to_link_rate(mgr->dpcd[1]), mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK); if (mgr->pbn_div == 0) { ret = -EINVAL; |