2 files changed, 21 insertions, 19 deletions

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index 3391e6739d06..dc9caab9488d 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -2553,14 +2553,14 @@ static int amd64_toggle_ecc_err_reporting(struct amd64_pvt *pvt, bool on)
 
                 if (on) {
                         if (reg->l & K8_MSR_MCGCTL_NBE)
-                                pvt->flags.ecc_report = 1;
+                                pvt->flags.nb_mce_enable = 1;
 
                         reg->l |= K8_MSR_MCGCTL_NBE;
                 } else {
                         /*
-                         * Turn off ECC reporting only when it was off before
+                         * Turn off NB MCE reporting only when it was off before
                          */
-                        if (!pvt->flags.ecc_report)
+                        if (!pvt->flags.nb_mce_enable)
                                 reg->l &= ~K8_MSR_MCGCTL_NBE;
                 }
         }
@@ -2571,22 +2571,11 @@ static int amd64_toggle_ecc_err_reporting(struct amd64_pvt *pvt, bool on)
         return 0;
 }
 
-/*
- * Only if 'ecc_enable_override' is set AND BIOS had ECC disabled, do "we"
- * enable it.
- */
 static void amd64_enable_ecc_error_reporting(struct mem_ctl_info *mci)
 {
         struct amd64_pvt *pvt = mci->pvt_info;
         u32 value, mask = K8_NBCTL_CECCEn | K8_NBCTL_UECCEn;
 
-        if (!ecc_enable_override)
-                return;
-
-        amd64_printk(KERN_WARNING,
-                "'ecc_enable_override' parameter is active, "
-                "Enabling AMD ECC hardware now: CAUTION\n");
-
         amd64_read_pci_cfg(pvt->misc_f3_ctl, K8_NBCTL, &value);
 
         /* turn on UECCn and CECCEn bits */
@@ -2611,6 +2600,8 @@ static void amd64_enable_ecc_error_reporting(struct mem_ctl_info *mci)
                         "This node reports that DRAM ECC is "
                         "currently Disabled; ENABLING now\n");
 
+                pvt->flags.nb_ecc_prev = 0;
+
                 /* Attempt to turn on DRAM ECC Enable */
                 value |= K8_NBCFG_ECC_ENABLE;
                 pci_write_config_dword(pvt->misc_f3_ctl, K8_NBCFG, value);
@@ -2625,7 +2616,10 @@ static void amd64_enable_ecc_error_reporting(struct mem_ctl_info *mci)
                         amd64_printk(KERN_DEBUG,
                                 "Hardware accepted DRAM ECC Enable\n");
                 }
+        } else {
+                pvt->flags.nb_ecc_prev = 1;
         }
+
         debugf0("NBCFG(2)= 0x%x  CHIPKILL= %s ECC_ENABLE= %s\n", value,
                 (value & K8_NBCFG_CHIPKILL) ? "Enabled" : "Disabled",
                 (value & K8_NBCFG_ECC_ENABLE) ? "Enabled" : "Disabled");
@@ -2644,12 +2638,18 @@ static void amd64_restore_ecc_error_reporting(struct amd64_pvt *pvt)
         value &= ~mask;
         value |= pvt->old_nbctl;
 
-        /* restore the NB Enable MCGCTL bit */
         pci_write_config_dword(pvt->misc_f3_ctl, K8_NBCTL, value);
 
+        /* restore previous BIOS DRAM ECC "off" setting which we force-enabled */
+        if (!pvt->flags.nb_ecc_prev) {
+                amd64_read_pci_cfg(pvt->misc_f3_ctl, K8_NBCFG, &value);
+                value &= ~K8_NBCFG_ECC_ENABLE;
+                pci_write_config_dword(pvt->misc_f3_ctl, K8_NBCFG, value);
+        }
+
+        /* restore the NB Enable MCGCTL bit */
         if (amd64_toggle_ecc_err_reporting(pvt, OFF))
-                amd64_printk(KERN_WARNING, "Error restoring ECC reporting over "
-                                           "MCGCTL!\n");
+                amd64_printk(KERN_WARNING, "Error restoring NB MCGCTL settings!\n");
 }
 
 /*
@@ -2690,8 +2690,9 @@ static int amd64_check_ecc_enabled(struct amd64_pvt *pvt)
                 if (!ecc_enable_override) {
                         amd64_printk(KERN_NOTICE, "%s", ecc_msg);
                         return -ENODEV;
+                } else {
+                        amd64_printk(KERN_WARNING, "Forcing ECC checking on!\n");
                 }
-                ecc_enable_override = 0;
         }
 
         return 0;
diff --git a/drivers/edac/amd64_edac.h b/drivers/edac/amd64_edac.h
index 41bc561e5981..0d4bf5638243 100644
--- a/drivers/edac/amd64_edac.h
+++ b/drivers/edac/amd64_edac.h
@@ -487,7 +487,8 @@ struct amd64_pvt {
         /* misc settings */
         struct flags {
                 unsigned long cf8_extcfg:1;
-                unsigned long ecc_report:1;
+                unsigned long nb_mce_enable:1;
+                unsigned long nb_ecc_prev:1;
         } flags;
 };