i3c: mipi-i3c-hci: Prevent DMA enqueue while ring is aborting or in error

Block the DMA enqueue path while a Ring abort is in progress or after an
error condition has been detected.

Previously, new transfers could be enqueued while the DMA Ring was being
aborted or while error handling was underway. This allowed enqueue and
error-recovery paths to run concurrently, potentially interfering with
each other and corrupting Ring state.

Introduce explicit enqueue blocking and a wait queue to serialize access:
enqueue operations now wait until abort or error handling has completed
before proceeding. Enqueue is unblocked once the Ring is safely restarted.

Note, there is only 1 ring bundle configured, and a transfer error causes
the controller to halt ring (bundle) operation, so there is only ever 1
outstanding error at a time.  Furthermore, a later patch ensures that only
the currently active transfer list can time out.  Consequently, the DMA
queue will not be unblocked while there are outstanding transfer errors or
timeouts.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260603090754.16252-4-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

0 files changed, 0 insertions, 0 deletions