We were using drm helpers to convert a timing into its bandwidth, its bandwidth into pbn, and its pbn into timeslots
These helpers -Did not take DSC timings into account -Used the link rate and lane count of the link's aux device, which are not the same as the link's current cap -Did not take FEC into account (FEC reduces the PBN per timeslot)
For converting timing into PBN, use the new function drm_dp_calc_pbn_mode_dsc that handles the DSC case
For converting PBN into time slots, amdgpu doesn't use the 'correct' atomic method (drm_dp_atomic_find_vcpi_slots), so don't add a new helper to cover our approach. Use the same means of calculating pbn per time slot as the DSC code.
Cc: Jerry Zuo Jerry.Zuo@amd.com Cc: Nicholas Kazlauskas nicholas.kazlauskas@amd.com Signed-off-by: David Francis David.Francis@amd.com --- .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c index 5f2c315b18ba..716d6577cdbd 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c @@ -189,8 +189,8 @@ bool dm_helpers_dp_mst_write_payload_allocation_table( int slots = 0; bool ret; int clock; - int bpp = 0; int pbn = 0; + int pbn_per_timeslot, bpp = 0;
aconnector = (struct amdgpu_dm_connector *)stream->dm_stream_context;
@@ -234,11 +234,18 @@ bool dm_helpers_dp_mst_write_payload_allocation_table(
bpp = bpp * 3;
- /* TODO need to know link rate */ - - pbn = drm_dp_calc_pbn_mode(clock, bpp); +#ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT + if (stream->timing.flags.DSC) + pbn = drm_dp_calc_pbn_mode_dsc(clock, + stream->timing.dsc_cfg.bits_per_pixel); + else +#endif + pbn = drm_dp_calc_pbn_mode(clock, bpp);
- slots = drm_dp_find_vcpi_slots(mst_mgr, pbn); + /* Convert kilobits per second / 64 (for 64 timeslots) to pbn (54/64 megabytes per second) */ + pbn_per_timeslot = dc_link_bandwidth_kbps( + stream->link, dc_link_get_link_cap(stream->link)) / (8 * 1000 * 54); + slots = DIV_ROUND_UP(pbn, pbn_per_timeslot); ret = drm_dp_mst_allocate_vcpi(mst_mgr, mst_port, pbn, slots);
if (!ret)