[PATCH V2 10/14] i3c: mipi-i3c-hci: Restart DMA ring correctly after dequeue abort

[Adrian Hunter]

The DMA dequeue path attempts to restart the ring after aborting an
in-flight transfer, but the current sequence is incomplete. The controller
must be brought out of the aborted state and the ring control registers
must be programmed in the correct order: first clearing ABORT, then
re-enabling the ring and asserting RUN_STOP to resume operation.

Add the missing controller resume step and update the ring control writes
so that the ring is restarted using the proper sequence.

Fixes: 9ad9a52cce282 ("i3c/master: introduce the mipi-i3c-hci driver")
Cc: stable at vger.kernel.org
Signed-off-by: Adrian Hunter <adrian.hunter at intel.com>
Reviewed-by: Frank Li <Frank.Li at nxp.com>
---


Changes in V2:

	Add Frank's Rev'd-by


 drivers/i3c/master/mipi-i3c-hci/dma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
index 239a195df7c7..41b83f07fdab 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dma.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
@@ -600,7 +600,9 @@ static bool hci_dma_dequeue_xfer(struct i3c_hci *hci,
 	}
 
 	/* restart the ring */
+	mipi_i3c_hci_resume(hci);
 	rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE);
+	rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE | RING_CTRL_RUN_STOP);
 
 	spin_unlock_irq(&hci->lock);
 
-- 
2.51.0