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* [RFC 0/7] drm/display/dp_tunnel: Add debugfs surface for BWA validation
@ 2026-05-11  5:40 Kunal Joshi
  2026-05-11  5:40 ` [RFC 1/7] drm/display/dp_tunnel: Add debugfs interface with info file Kunal Joshi
                   ` (8 more replies)
  0 siblings, 9 replies; 10+ messages in thread
From: Kunal Joshi @ 2026-05-11  5:40 UTC (permalink / raw)
  To: intel-gfx, intel-xe; +Cc: imre.deak, jani.nikula, Kunal Joshi

Add a debugfs surface to the DRM display DP-tunnel core so IGT
(kms_tbt) can drive deterministic tests of Bandwidth Allocation
Mode on Thunderbolt / USB4 docks without depending on transient
sink behaviour.

Three debugfs files are exposed per tunnel:
  - info       (read-only)  estimated BW, allocated BW, DPRX caps, BWA state
  - bw_alloc_enable (r/w)   toggle BWA on/off
  - bw_limit        (r/w)   inject a BW cap for mode-filtering pressure

Patches 1-3 add the DRM-core helpers, 4-5 wire them into i915,
and 6-7 fix two latent BWA bugs found while testing:
  - allocated_bw not synced after BWA enable (teardown loop)
  - MST children lose dp_tunnel/ after tunnel re-detect

Companion IGT series (kms_tbt) posted separately.

Kunal Joshi (7):
  drm/display/dp_tunnel: Add debugfs interface with info file
  drm/display/dp_tunnel: Add bw_alloc_enable debugfs knob
  drm/display/dp_tunnel: Add bw_limit debugfs cap for BW pressure
    injection
  drm/i915/dp_tunnel: Wire up DP tunnel debugfs from DRM core
  drm/i915/display: Expose DP tunnel debugfs under each connector
  drm/display/dp_tunnel: Sync SW allocated_bw after enabling BW alloc
  drm/i915/dp_tunnel: Re-attach dp_tunnel debugfs to MST children on
    re-detect

 drivers/gpu/drm/display/drm_dp_tunnel.c       | 402 +++++++++++++++++-
 .../drm/i915/display/intel_display_debugfs.c  |  22 +
 drivers/gpu/drm/i915/display/intel_dp.c       |  11 +
 drivers/gpu/drm/i915/display/intel_dp_mst.c   |  11 +
 .../gpu/drm/i915/display/intel_dp_tunnel.c    |  50 ++-
 include/drm/display/drm_dp_tunnel.h           |  17 +
 6 files changed, 511 insertions(+), 2 deletions(-)

-- 
2.25.1


^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2026-05-11 20:10 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
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2026-05-11  5:40 [RFC 0/7] drm/display/dp_tunnel: Add debugfs surface for BWA validation Kunal Joshi
2026-05-11  5:40 ` [RFC 1/7] drm/display/dp_tunnel: Add debugfs interface with info file Kunal Joshi
2026-05-11  5:40 ` [RFC 2/7] drm/display/dp_tunnel: Add bw_alloc_enable debugfs knob Kunal Joshi
2026-05-11  5:40 ` [RFC 3/7] drm/display/dp_tunnel: Add bw_limit debugfs cap for BW pressure injection Kunal Joshi
2026-05-11  5:40 ` [RFC 4/7] drm/i915/dp_tunnel: Wire up DP tunnel debugfs from DRM core Kunal Joshi
2026-05-11  5:40 ` [RFC 5/7] drm/i915/display: Expose DP tunnel debugfs under each connector Kunal Joshi
2026-05-11  5:40 ` [RFC 6/7] drm/display/dp_tunnel: Sync SW allocated_bw after enabling BW alloc Kunal Joshi
2026-05-11  5:40 ` [RFC 7/7] drm/i915/dp_tunnel: Re-attach dp_tunnel debugfs to MST children on re-detect Kunal Joshi
2026-05-11 14:54 ` ✓ i915.CI.BAT: success for drm/display/dp_tunnel: Add debugfs surface for BWA validation Patchwork
2026-05-11 20:10 ` ✗ i915.CI.Full: failure " Patchwork

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