i3c: master: Move entdaa error suppression

Prepare to fix improper Mx positive error propagation in later commits
by handling Mx error codes where the i3c_ccc_cmd command is allocated.
The CCC ENTDAA is invoked with i3c_master_entdaa_locked() and yields
error I3C_ERROR_M2 if there are no devices active on the bus. Some
controllers may also yield if there are no more devices need an dynamic
address, since the sequence do always end in a NACK. Handle inside
i3c_master_entdaa_locked(), checking cmd->err directly. Both call sites
are updated, adi_i3c_master_do_daa() and cdns_i3c_master_do_daa().

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Jorge Marques <jorge.marques@analog.com>
Link: https://patch.msgid.link/20260323-ad4062-positive-error-fix-v3-2-30bdc68004be@analog.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: gastmaier

drivers/i3c/master.c

@@ -1077,6 +1077,10 @@ int i3c_master_entdaa_locked(struct i3c_master_controller *master)
 	ret = i3c_master_send_ccc_cmd_locked(master, &cmd);
 	i3c_ccc_cmd_dest_cleanup(&dest);
 
+	/* No active devices need an address. */
+	if (ret && cmd.err == I3C_ERROR_M2)
+		ret = 0;
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(i3c_master_entdaa_locked);

drivers/i3c/master/adi-i3c-master.c

@@ -655,8 +655,7 @@ static int adi_i3c_master_do_daa(struct i3c_master_controller *m)
 
 	writel(irq_mask, master->regs + REG_IRQ_MASK);
 
-	/* DAA always finishes with CE2_ERROR or NACK_RESP */
-	if (ret && ret != I3C_ERROR_M2)
+	if (ret)
 		return ret;
 
 	/* Add I3C devices discovered */

drivers/i3c/master/i3c-master-cdns.c

@@ -1143,7 +1143,7 @@ static int cdns_i3c_master_do_daa(struct i3c_master_controller *m)
 	}
 
 	ret = i3c_master_entdaa_locked(&master->base);
-	if (ret && ret != I3C_ERROR_M2)
+	if (ret)
 		return ret;
 
 	newdevs = readl(master->regs + DEVS_CTRL) & DEVS_CTRL_DEVS_ACTIVE_MASK;