drivers: i3c: cdns: handle ibi len of 0

Section 4.3.7.3.6 of the I3C v1.2 specification states that a value of
0 for the max ibi size indicates an unlimited payload size. Set it to
the max it can be configured for.

Signed-off-by: Ryan McClelland <[email protected]>

Author: XenuIsWatching

drivers/i3c/i3c_cdns.c

@@ -1088,7 +1088,18 @@ static int cdns_i3c_controller_ibi_enable(const struct device *dev, struct i3c_d
 	sir_cfg = SIR_MAP_DEV_ROLE(I3C_BCR_DEVICE_ROLE(target->bcr)) |
 		  SIR_MAP_DEV_DA(target->dynamic_addr);
 	if (i3c_ibi_has_payload(target)) {
-		sir_cfg |= SIR_MAP_DEV_PL(target->data_length.max_ibi);
+		/*
+		 * the I3C spec says that a len of 0x00, means no limit, but the cdns i3c doesn't
+		 * reconigize stops when loading a new word in the FIFO, so if multiple ibis come in
+		 * quick succession, then they may be all in the same fifo word and may not be read
+		 * correctly.
+		 */
+		if (target->data_length.max_ibi == 0x00) {
+			sir_cfg |= SIR_MAP_DEV_PL(
+				MIN(SIR_MAP_PL_MAX, CONFIG_I3C_IBI_MAX_PAYLOAD_SIZE));
+		} else {
+			sir_cfg |= SIR_MAP_DEV_PL(target->data_length.max_ibi);
+		}
 	} else {
 		/* Set to 1 for MDB */
 		sir_cfg |= SIR_MAP_DEV_PL(1);