Commit 6e13d652 authored by Frank Li's avatar Frank Li Committed by Alexandre Belloni
Browse files

i3c: master: svc: fix probe failure when no i3c device exist 



I3C masters are expected to support hot-join. This means at initialization
time we might not yet discover any device and this should not be treated
as a fatal error.

During the DAA procedure which happens at probe time, if no device has
joined, all CCC will be NACKed (from a bus perspective). This leads to an
early return with an error code which fails the probe of the master.

Let's avoid this by just telling the core through an I3C_ERROR_M2
return command code that no device was discovered, which is a valid
situation. This way the master will no longer bail out and fail to probe
for a wrong reason.

Cc: stable@vger.kernel.org
Fixes: dd3c5284 ("i3c: master: svc: Add Silvaco I3C master driver")
Signed-off-by: default avatarFrank Li <Frank.Li@nxp.com>
Acked-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230831141324.2841525-1-Frank.Li@nxp.com


Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent c6a75504

drivers/i3c/master/svc-i3c-master.c

+12 −2
Original line number Diff line number Diff line
@@ -790,6 +790,10 @@ static int svc_i3c_master_do_daa_locked(struct svc_i3c_master *master, 
				 */

				break;

			} else if (SVC_I3C_MSTATUS_NACKED(reg)) {

				/* No I3C devices attached */

				if (dev_nb == 0)

					break;



				/*

				 * A slave device nacked the address, this is

				 * allowed only once, DAA will be stopped and
@@ -1264,11 +1268,17 @@ static int svc_i3c_master_send_ccc_cmd(struct i3c_master_controller *m, 
{

	struct svc_i3c_master *master = to_svc_i3c_master(m);

	bool broadcast = cmd->id < 0x80;

	int ret;



	if (broadcast)

		return svc_i3c_master_send_bdcast_ccc_cmd(master, cmd);

		ret = svc_i3c_master_send_bdcast_ccc_cmd(master, cmd);

	else

		return svc_i3c_master_send_direct_ccc_cmd(master, cmd);

		ret = svc_i3c_master_send_direct_ccc_cmd(master, cmd);



	if (ret)

		cmd->err = I3C_ERROR_M2;



	return ret;

}



static int svc_i3c_master_priv_xfers(struct i3c_dev_desc *dev,