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Commit 8358378b authored by Guenter Roeck's avatar Guenter Roeck
Browse files

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



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

Reported-by: default avatarRussell King <linux@armlinux.org.uk>
Fixes: e84bd953 ("hwmon: (it87) Add support for second Super-IO chip")
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent dd7406dd

drivers/hwmon/it87.c

+19 −5
Original line number Diff line number Diff line
@@ -3198,7 +3198,7 @@ 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;
@@ -3208,15 +3208,29 @@ 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) {