diff --git a/drivers/hwmon/fam15h_power.c b/drivers/hwmon/fam15h_power.c index b7494af1e4a9ba8cb6952c83d96b845f19f9e7fd..37a8fc92b44acf50a16d086c9983a9794c03b838 100644 --- a/drivers/hwmon/fam15h_power.c +++ b/drivers/hwmon/fam15h_power.c @@ -122,6 +122,38 @@ static bool __devinit fam15h_power_is_internal_node0(struct pci_dev *f4) return true; } +/* + * Newer BKDG versions have an updated recommendation on how to properly + * initialize the running average range (was: 0xE, now: 0x9). This avoids + * counter saturations resulting in bogus power readings. + * We correct this value ourselves to cope with older BIOSes. + */ +static void __devinit tweak_runavg_range(struct pci_dev *pdev) +{ + u32 val; + const struct pci_device_id affected_device = { + PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) }; + + /* + * let this quirk apply only to the current version of the + * northbridge, since future versions may change the behavior + */ + if (!pci_match_id(&affected_device, pdev)) + return; + + pci_bus_read_config_dword(pdev->bus, + PCI_DEVFN(PCI_SLOT(pdev->devfn), 5), + REG_TDP_RUNNING_AVERAGE, &val); + if ((val & 0xf) != 0xe) + return; + + val &= ~0xf; + val |= 0x9; + pci_bus_write_config_dword(pdev->bus, + PCI_DEVFN(PCI_SLOT(pdev->devfn), 5), + REG_TDP_RUNNING_AVERAGE, val); +} + static void __devinit fam15h_power_init_data(struct pci_dev *f4, struct fam15h_power_data *data) { @@ -155,6 +187,13 @@ static int __devinit fam15h_power_probe(struct pci_dev *pdev, struct device *dev; int err; + /* + * though we ignore every other northbridge, we still have to + * do the tweaking on _each_ node in MCM processors as the counters + * are working hand-in-hand + */ + tweak_runavg_range(pdev); + if (!fam15h_power_is_internal_node0(pdev)) { err = -ENODEV; goto exit;