The second interface can be found on X370, X470 and X570 according to the bugzilla entry. I only tested with X570 on an ASRock X570 Taichi: $ lspci -nnv -d 1022:790b 00:14.0 SMBus [0c05]: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller [1022:790b] (rev 61) Subsystem: ASRock Incorporation FCH SMBus Controller [1849:ffff] Flags: 66MHz, medium devsel Kernel driver in use: piix4_smbus Kernel modules: i2c_piix4, sp5100_tco Before the patch: $ i2cdetect -l | grep PIIX4 i2c-1 unknown SMBus PIIX4 adapter port 2 at 0b00 N/A i2c-0 unknown SMBus PIIX4 adapter port 0 at 0b00 N/A After the patch: $ i2cdetect -l | grep PIIX4 i2c-1 unknown SMBus PIIX4 adapter port 2 at 0b00 N/A i2c-2 unknown SMBus PIIX4 adapter port 1 at 0b20 N/A i2c-0 unknown SMBus PIIX4 adapter port 0 at 0b00 N/A Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202587 Reported-by: Adam Honse <calcprogrammer1@xxxxxxxxx> Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx> --- Hi, The Bugzilla entry contains a second change, which reduces the timeouts for quicker operation. I did not include that change, since I do not know if this is a good idea for all devices supported by this driver. In any case it should be a separate patch. Let's get the interface working for now. -- Sebastian --- drivers/i2c/busses/i2c-piix4.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c index 30ded6422e7b..3e89143a0ecf 100644 --- a/drivers/i2c/busses/i2c-piix4.c +++ b/drivers/i2c/busses/i2c-piix4.c @@ -976,9 +976,11 @@ static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id) } } - if (dev->vendor == PCI_VENDOR_ID_AMD && - dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) { - retval = piix4_setup_sb800(dev, id, 1); + if (dev->vendor == PCI_VENDOR_ID_AMD) { + if (dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS || + dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) { + retval = piix4_setup_sb800(dev, id, 1); + } } if (retval > 0) { -- 2.25.1
