i3c: master: Reconcile dynamic addresses after DAA

After Dynamic Address Assignment (DAA), there may be cases where
devices have been assigned dynamic addresses on the bus, but are not
successfully registered in the device model.  This can happen, for
example, if errors occur during device addition, leaving the bus state
and software state inconsistent.

Introduce a reconciliation step to resolve such inconsistencies.

Scan all address slots marked as I3C devices by the bus, and compare
them against the set of devices currently registered.  For any dynamic
address that is marked occupied but has no corresponding i3c_dev_desc,
probe for device presence using a GETSTATUS CCC.

Retry the probe (with exponential backoff delay) to handle transient NACK
conditions.  If a device responds, register it via
i3c_master_add_i3c_dev_locked().  Otherwise, free the address
slot so it may be reused in future DAA operations.

Note, i3c_master_add_i3c_dev_locked() may fail (again), in which case the
dynamic address remains marked as occupied.  A future DAA will try again.

This also handles a corner case where a device is assigned a dynamic
address but not successfully added, and subsequently loses that address
(e.g. due to power management).  If DAA is run again, the device may
receive a new dynamic address while the old one remains marked as
occupied.  Repeated occurrences of this scenario could eventually
exhaust the dynamic address space.  The reconciliation step ensures that
stale addresses are detected and freed, preventing address leakage.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260612080107.11606-8-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

0 files changed, 0 insertions, 0 deletions