cxl/port: Restart port enumeration when a sibling adds the dport first

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Endpoint probes can race while enumerating a shared switch. If a
sibling probe adds the dport first, the losing probe finds the dport
already present, gets -EBUSY, and fails to enumerate the endpoint.

Treat this race the same as the existing port-created case by
restarting the port walk, allowing it to find the existing dport
and continue enumeration.

This race was discovered while testing a cxl_test mixed-granularity
topology, where twelve endpoints behind shared switches are probed in
parallel during module load.

Fixes: 4f06d81e7c ("cxl: Defer dport allocation for switch ports")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Tested-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Link: https://patch.msgid.link/20260714020438.1822669-1-alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

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Alison Schofield 2026-07-13 19:04:35 -07:00 • committed by Dave Jiang

parent 77b814c183

commit a623128bc2

1 changed files with 2 additions and 2 deletions

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drivers/cxl/core/port.c

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