From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org
Cc: Adrian Hunter <adrian.hunter@intel.com>,
	Frank Li <Frank.Li@nxp.com>,
	Mukesh Savaliya <mukesh.savaliya@oss.qualcomm.com>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.1.y] i3c: master: Do not treat master device as a duplicate target
Date: Wed,  9 Sep 2026 21:20:58 -0400
Message-ID: <20260910012058.3847485-1-sashal@kernel.org>
In-Reply-To: <2026090412-bruising-crispy-d9d5@gregkh>
References: <2026090412-bruising-crispy-d9d5@gregkh>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Adrian Hunter <adrian.hunter@intel.com>

[ Upstream commit 4dc1b3eeba7991905a5b5b8129ebea51be7d87b7 ]

i3c_master_search_i3c_dev_duplicate() searches the bus for another I3C
device with the same PID as the reference device.  The search can match
master->this, causing the controller itself to be returned as a
duplicate.

Since the controller is not a target device, it cannot be a duplicate of
one.  Exclude master->this from matching so that the function only
returns real duplicate target devices.

Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure")
Cc: stable@vger.kernel.org
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Mukesh Savaliya <mukesh.savaliya@oss.qualcomm.com>
Link: https://patch.msgid.link/20260807145638.168865-4-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
[ adjusted the duplicate-device comparison to match the older branch’s PID handling without nonzero-PID checks. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i3c/master.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 09d7b707c7b18..2fb403a34cf39 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -1976,7 +1976,8 @@ i3c_master_search_i3c_dev_duplicate(struct i3c_dev_desc *refdev)
 	struct i3c_dev_desc *i3cdev;
 
 	i3c_bus_for_each_i3cdev(&master->bus, i3cdev) {
-		if (i3cdev != refdev && i3cdev->info.pid == refdev->info.pid)
+		if (i3cdev != refdev && i3cdev->info.pid == refdev->info.pid &&
+		    i3cdev != master->this)
 			return i3cdev;
 	}
 
-- 
2.53.0