Received-SPF: pass (google.com: domain of linux-kernel+bounces-81950-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
From: Eddie James <eajames@linux.ibm.com>
To: linux-fsi@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org,
        devicetree@vger.kernel.org, andi.shyti@kernel.org,
        eajames@linux.ibm.com, alistair@popple.id.au, joel@jms.id.au,
        jk@ozlabs.org, robh@kernel.org, krzysztof.kozlowski+dt@linaro.org,
        conor+dt@kernel.org, lakshmiy@us.ibmcom
Subject: [PATCH v2 02/31] fsi: Improve master indexing
Date: Mon, 26 Feb 2024 10:52:52 -0600
Message-Id: <20240226165321.91976-3-eajames@linux.ibm.com>
In-Reply-To: <20240226165321.91976-1-eajames@linux.ibm.com>
References: <20240226165321.91976-1-eajames@linux.ibm.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

Master indexing is problematic if a hub is rescanned while the
root master is being rescanned. Move the IDA free below the device
unregistration, lock the scan mutex in the probe function, and
request a specific idx in the hub driver.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/fsi/fsi-core.c       | 12 +++++-------
 drivers/fsi/fsi-master-hub.c |  2 ++
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 7bf0c96fc017..1c687eb021a0 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -1271,7 +1271,6 @@ static struct class fsi_master_class = {
 int fsi_master_register(struct fsi_master *master)
 {
 	int rc;
-	struct device_node *np;
 
 	mutex_init(&master->scan_lock);
 
@@ -1295,14 +1294,13 @@ int fsi_master_register(struct fsi_master *master)
 	rc = device_register(&master->dev);
 	if (rc) {
 		ida_free(&master_ida, master->idx);
-		goto out;
-	}
+	} else {
+		struct device_node *np = dev_of_node(&master->dev);
 
-	np = dev_of_node(&master->dev);
-	if (!of_property_read_bool(np, "no-scan-on-init")) {
-		fsi_master_scan(master);
+		if (!of_property_read_bool(np, "no-scan-on-init"))
+			fsi_master_scan(master);
 	}
-out:
+
 	mutex_unlock(&master->scan_lock);
 	return rc;
 }
diff --git a/drivers/fsi/fsi-master-hub.c b/drivers/fsi/fsi-master-hub.c
index 6d8b6e8854e5..36da643b3201 100644
--- a/drivers/fsi/fsi-master-hub.c
+++ b/drivers/fsi/fsi-master-hub.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 
 #include "fsi-master.h"
+#include "fsi-slave.h"
 
 #define FSI_ENGID_HUB_MASTER		0x1c
 
@@ -229,6 +230,7 @@ static int hub_master_probe(struct device *dev)
 	hub->master.dev.release = hub_master_release;
 	hub->master.dev.of_node = of_node_get(dev_of_node(dev));
 
+	hub->master.idx = fsi_dev->slave->link + 1;
 	hub->master.n_links = links;
 	hub->master.read = hub_master_read;
 	hub->master.write = hub_master_write;
-- 
2.39.3