Patch "hwmon: (it87) Avoid registering the same chip on both SIO addresses" has been added to the 4.10-stable tree

Patch "hwmon: (it87) Avoid registering the same chip on both SIO addresses" has been added to the 4.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    hwmon: (it87) Avoid registering the same chip on both SIO addresses

to the 4.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     hwmon-it87-avoid-registering-the-same-chip-on-both-sio-addresses.patch
and it can be found in the queue-4.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 8358378b22518d92424597503d3c1cd302a490b6 Mon Sep 17 00:00:00 2001
From: Guenter Roeck <linux@roeck-us.net>
Date: Sun, 12 Mar 2017 06:18:58 -0700
Subject: hwmon: (it87) Avoid registering the same chip on both SIO addresses

From: Guenter Roeck <linux@roeck-us.net>

commit 8358378b22518d92424597503d3c1cd302a490b6 upstream.

IT8705F is known to respond on both SIO addresses. Registering it twice
may result in system lockups.

Reported-by: Russell King <linux@armlinux.org.uk>
Fixes: e84bd9535e2b ("hwmon: (it87) Add support for second Super-IO chip")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/hwmon/it87.c |   24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

--- a/drivers/hwmon/it87.c
+++ b/drivers/hwmon/it87.c
@@ -3115,7 +3115,7 @@ static int __init sm_it87_init(void)
 {
 	int sioaddr[2] = { REG_2E, REG_4E };
 	struct it87_sio_data sio_data;
-	unsigned short isa_address;
+	unsigned short isa_address[2];
 	bool found = false;
 	int i, err;
 
@@ -3125,15 +3125,29 @@ static int __init sm_it87_init(void)
 
 	for (i = 0; i < ARRAY_SIZE(sioaddr); i++) {
 		memset(&sio_data, 0, sizeof(struct it87_sio_data));
-		isa_address = 0;
-		err = it87_find(sioaddr[i], &isa_address, &sio_data);
-		if (err || isa_address == 0)
+		isa_address[i] = 0;
+		err = it87_find(sioaddr[i], &isa_address[i], &sio_data);
+		if (err || isa_address[i] == 0)
 			continue;
+		/*
+		 * Don't register second chip if its ISA address matches
+		 * the first chip's ISA address.
+		 */
+		if (i && isa_address[i] == isa_address[0])
+			break;
 
-		err = it87_device_add(i, isa_address, &sio_data);
+		err = it87_device_add(i, isa_address[i], &sio_data);
 		if (err)
 			goto exit_dev_unregister;
+
 		found = true;
+
+		/*
+		 * IT8705F may respond on both SIO addresses.
+		 * Stop probing after finding one.
+		 */
+		if (sio_data.type == it87)
+			break;
 	}
 
 	if (!found) {


Patches currently in stable-queue which might be from linux@roeck-us.net are

queue-4.10/hwmon-it87-avoid-registering-the-same-chip-on-both-sio-addresses.patch