Commit fc72af3a authored Aug 03, 2016 by Guenter Roeck

hwmon: (nct6775) Do not accept force_id unless chip is found

Since commit 698a7c24 ("hwmon: (nct6775) Support two SuperIO chips
in the same system"), the driver supports two Super-IO chips. This has
the undesirable side effect that force_id always detects a second chip
at address 0xfff8, even if no chip exists at that address.

nct6775: Found NCT6793D or compatible chip at 0x4e:0xfff8

If no chip at all is found at a given SIO address, it does not make sense
to instantiate it. Limit force_id to only work if some chip is found,
that is if the chip ID returns a value other than 0xffff.

Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

parent f9f7bb3a

drivers/hwmon/nct6775.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -4232,11 +4232,11 @@ static int __init nct6775_find(int sioaddr, struct nct6775_sio_data *sio_data)
		if (err)
		return err;

		if (force_id)
		val = (superio_inb(sioaddr, SIO_REG_DEVID) << 8) \|
		superio_inb(sioaddr, SIO_REG_DEVID + 1);
		if (force_id && val != 0xffff)
		val = force_id;
		else
		val = (superio_inb(sioaddr, SIO_REG_DEVID) << 8)
		\| superio_inb(sioaddr, SIO_REG_DEVID + 1);

		switch (val & SIO_ID_MASK) {
		case SIO_NCT6106_ID:
		sio_data->kind = nct6106;

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