[PATCH 02/16] i3c: mipi-i3c-hci: Preserve RUN bit when aborting DMA ring

[Adrian Hunter]

The MIPI I3C HCI specification does not require the DMA ring RUN bit
(RUN_STOP) to be cleared when issuing an ABORT.

Adjust the RING_CONTROL handling to set ABORT without clearing RUN_STOP,
bringing the driver into alignment with the specification.

According to the specification, that allows the DMA ring to continue to
receive IBIs, although currently ABORT is only used in an error path so
the change has very little effect in practice.

Fixes: b795e68bf3073 ("i3c: mipi-i3c-hci: Correct RING_CTRL_ABORT handling in DMA dequeue")
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
 drivers/i3c/master/mipi-i3c-hci/dma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
index e487ef52f6b4..4cd32e3afa7b 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dma.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
@@ -554,7 +554,7 @@ static bool hci_dma_dequeue_xfer(struct i3c_hci *hci,
 	if (ring_status & RING_STATUS_RUNNING) {
 		/* stop the ring */
 		reinit_completion(&rh->op_done);
-		rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE | RING_CTRL_ABORT);
+		rh_reg_write(RING_CONTROL, rh_reg_read(RING_CONTROL) | RING_CTRL_ABORT);
 		wait_for_completion_timeout(&rh->op_done, HZ);
 		ring_status = rh_reg_read(RING_STATUS);
 		if (ring_status & RING_STATUS_RUNNING) {
-- 
2.51.0