hwmon: (k10temp) Do not blacklist known working CPU models

When detecting AM2+ or AM3 socket with DDR2, only blacklist cores
which are known to exist in AM2+ format.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: stable@kernel.org

1 files changed, 12 insertions, 2 deletions

diff --git a/drivers/hwmon/k10temp.c b/drivers/hwmon/k10temp.c
index 099a2138cdf6..da5a2404cd3e 100644
--- a/drivers/hwmon/k10temp.c
+++ b/drivers/hwmon/k10temp.c
@@ -112,11 +112,21 @@ static bool __devinit has_erratum_319(struct pci_dev *pdev)
         if (pkg_type != CPUID_PKGTYPE_AM2R2_AM3)
                 return false;
 
-        /* Differentiate between AM2+ (bad) and AM3 (good) */
+        /* DDR3 memory implies socket AM3, which is good */
         pci_bus_read_config_dword(pdev->bus,
                                   PCI_DEVFN(PCI_SLOT(pdev->devfn), 2),
                                   REG_DCT0_CONFIG_HIGH, &reg_dram_cfg);
-        return !(reg_dram_cfg & DDR3_MODE);
+        if (reg_dram_cfg & DDR3_MODE)
+                return false;
+
+        /*
+         * Unfortunately it is possible to run a socket AM3 CPU with DDR2
+         * memory. We blacklist all the cores which do exist in socket AM2+
+         * format. It still isn't perfect, as RB-C2 cores exist in both AM2+
+         * and AM3 formats, but that's the best we can do.
+         */
+        return boot_cpu_data.x86_model < 4 ||
+               (boot_cpu_data.x86_model == 4 && boot_cpu_data.x86_mask <= 2);
 }
 
 static int __devinit k10temp_probe(struct pci_dev *pdev,