Commit 78f63ae4 authored by Adrian Hunter's avatar Adrian Hunter Committed by Alexandre Belloni
Browse files

i3c: mipi-i3c-hci: Reset RING_OPERATION1 fields during init 



The MIPI I3C HCI specification does not define reset values for
RING_OPERATION1 fields, and some controllers (e.g., Intel) do not clear
them during a software reset.  Ensure the ring pointers are explicitly
set to zero during bus initialization to avoid inconsistent state.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: default avatarFrank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260113072702.16268-2-adrian.hunter@intel.com


Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 3502cea9

drivers/i3c/master/mipi-i3c-hci/dma.c

+8 −0
Original line number Diff line number Diff line
@@ -340,6 +340,14 @@ static int hci_dma_init(struct i3c_hci *hci) 
		rh_reg_write(INTR_SIGNAL_ENABLE, regval);



ring_ready:

		/*

		 * The MIPI I3C HCI specification does not document reset values for

		 * RING_OPERATION1 fields and some controllers (e.g. Intel controllers)

		 * do not reset the values, so ensure the ring pointers are set to zero

		 * here.

		 */

		rh_reg_write(RING_OPERATION1, 0);



		rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE |

					   RING_CTRL_RUN_STOP);

	}