Intel-XE Archive on lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH v2 0/2] Fix MST VCPI lookup and modeset-lock splat
@ 2026-05-04 10:11 Suraj Kandpal
  2026-05-04 10:11 ` [PATCH v2 1/2] drm/i915/hdcp: Use new MST topology state in intel_conn_to_vcpi() Suraj Kandpal
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: Suraj Kandpal @ 2026-05-04 10:11 UTC (permalink / raw)
  To: intel-xe, intel-gfx
  Cc: ankit.k.nautiyal, fnu.vishwanatha, santhosh.reddy.guddati,
	Suraj Kandpal

intel_conn_to_vcpi() is called from the HDCP enable path in commit_tail
to look
up the VCPI of the MST stream that HDCP is being enabled on. Today it
reads the
topology state directly from mgr->base.state and takes mgr->base.lock
with the
in-flight state->base.acquire_ctx.

This breaks in two ways on MST + HDCP, especially when an
ALLOCATE_PAYLOAD
transaction is being driven on the mgr just before HDCP enable runs:

- mgr->base.state's payload list is being mutated in place by the MST
  payload code, so drm_atomic_get_mst_payload_state() can fail to find
  the entry for this connector's port. That trips drm_WARN_ON(!payload)
  and HDCP ends up programmed with VCPI 0.

- By the time we reach commit_tail/encoder enable,
  state->base.acquire_ctx
  is no longer valid for acquiring new modeset locks. Taking
  mgr->base.lock here produces a modeset-lock splat.

This series fixes both.

Suraj Kandpal (2):
  drm/i915/hdcp: Use new MST topology state in intel_conn_to_vcpi()
  drm/i915/hdcp: Drop mgr->base.lock acquisition in intel_conn_to_vcpi()

 drivers/gpu/drm/i915/display/intel_hdcp.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

-- 
2.34.1


^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-05-04 17:00 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-05-04 10:11 [PATCH v2 0/2] Fix MST VCPI lookup and modeset-lock splat Suraj Kandpal
2026-05-04 10:11 ` [PATCH v2 1/2] drm/i915/hdcp: Use new MST topology state in intel_conn_to_vcpi() Suraj Kandpal
2026-05-04 10:11 ` [PATCH v2 2/2] drm/i915/hdcp: Drop mgr->base.lock acquisition " Suraj Kandpal
2026-05-04 12:50 ` ✓ CI.KUnit: success for Fix MST VCPI lookup and modeset-lock splat (rev2) Patchwork
2026-05-04 14:01 ` ✓ Xe.CI.BAT: " Patchwork
2026-05-04 17:00 ` ✓ Xe.CI.FULL: " Patchwork

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox