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| author | Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> | 2023-03-24 16:51:25 +0300 |
|---|---|---|
| committer | Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> | 2023-04-05 11:08:14 +0300 |
| commit | 764b1c8df40daf618b293b367f9be1f4fcd1b6fb (patch) | |
| tree | 8a648b81ce4fd56b9ecf4e0579783a2bd8ecd64e /drivers/gpu | |
| parent | aaee4bbe8a1aa6833d6c42c7015ae63c489fdeeb (diff) | |
| download | linux-764b1c8df40daf618b293b367f9be1f4fcd1b6fb.tar.xz | |
drm/i915: Implement UHBR bandwidth check
According to spec, we should check if output_bpp * pixel_rate is less
than DDI clock * 72, if UHBR is used.
v2: - s/pipe_config/crtc_state/ (Jani Nikula)
- Merged previous patch into that one, to remove empty function(Jani Nikula)
v3: - Make that constraint check to be DSC-related only
- Limit this to only DISPLAY_VER <= 13
v4: - Move constraint check to the top(Vinod Govindapillai)
HSDES: 1406899791
BSPEC: 49259
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Reviewed-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230324135125.6720-1-stanislav.lisovskiy@intel.com
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp_mst.c | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index fe01fdf36cfd..a88b852c437c 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -45,6 +45,27 @@ #include "intel_hotplug.h" #include "skl_scaler.h" +static int intel_dp_mst_check_constraints(struct drm_i915_private *i915, int bpp, + const struct drm_display_mode *adjusted_mode, + struct intel_crtc_state *crtc_state, + bool dsc) +{ + if (intel_dp_is_uhbr(crtc_state) && DISPLAY_VER(i915) <= 13 && dsc) { + int output_bpp = bpp; + /* DisplayPort 2 128b/132b, bits per lane is always 32 */ + int symbol_clock = crtc_state->port_clock / 32; + + if (output_bpp * adjusted_mode->crtc_clock >= + symbol_clock * 72) { + drm_dbg_kms(&i915->drm, "UHBR check failed(required bw %d available %d)\n", + output_bpp * adjusted_mode->crtc_clock, symbol_clock * 72); + return -EINVAL; + } + } + + return 0; +} + static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, struct intel_crtc_state *crtc_state, int max_bpp, @@ -81,12 +102,16 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, } for (bpp = max_bpp; bpp >= min_bpp; bpp -= step) { + drm_dbg_kms(&i915->drm, "Trying bpp %d\n", bpp); + + ret = intel_dp_mst_check_constraints(i915, bpp, adjusted_mode, crtc_state, dsc); + if (ret) + continue; + crtc_state->pbn = drm_dp_calc_pbn_mode(adjusted_mode->crtc_clock, dsc ? bpp << 4 : bpp, dsc); - drm_dbg_kms(&i915->drm, "Trying bpp %d\n", bpp); - slots = drm_dp_atomic_find_time_slots(state, &intel_dp->mst_mgr, connector->port, crtc_state->pbn); @@ -104,8 +129,8 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, } } - /* Despite slots are non-zero, we still failed the atomic check */ - if (ret && slots >= 0) + /* We failed to find a proper bpp/timeslots, return error */ + if (ret) slots = ret; if (slots < 0) { |