--- linux-2.6.15/arch/i386/kernel/cpu/cpufreq/powernow-k8.c	2006-03-14 23:10:35.000000000 +0100
+++ linux-2.6.15/arch/i386/kernel/cpu/cpufreq/powernow-k8.c	2006-03-16 19:03:17.000000000 +0100
@@ -277,7 +277,7 @@ static int transition_fid_vid(struct pow
 		return 1;
 	}
 
-	dprintk("transitioned (cpu%d): new fid 0x%x, vid 0x%x\n",
+	printk(KERN_INFO PFX "transitioned (cpu%d): new fid 0x%x, vid 0x%x\n",
 		smp_processor_id(), data->currfid, data->currvid);
 
 	return 0;
@@ -552,6 +552,113 @@ static void print_basics(struct powernow
 		printk(KERN_INFO PFX "Only %d pstates on battery\n", data->batps);
 }
 
+/* pnforce version 0.01a 
+   The pnforce_setup() and get_forced_vid() functions have been
+   written by Flavio Chierichetti (flavio -at- lightless -dot- org)
+   and have been released under the GPL2.
+
+   BE AWARE THAT THESE FUNCTIONS COME WITH ABSOLUTELY NO WARRANTY.
+   THEY MAY MELT YOUR CPU AND/OR YOUR SYSTEM.
+   I CAN'T PROVIDE SUPPORT FOR THEIR USE OR THEIR MISUSE.
+
+   Be aware that I'm not an hardware or a kernel expert.
+
+   That said, they seem to work for my cpu.
+
+   --
+
+   To force the use of some "vid"s, you have to pass the
+   "pnforce=" option at the kernel boot.
+   
+   The option format is
+     pnforce=fid1,forced_vid1[:fid2,forced_vid2[...]]
+   All numbers should be written in decimal.
+
+   You can't add new fid/vid couples to the pst table - you can only
+   change existing ones.
+
+   For example, to set 1250mV for 1800MHz, 1150mV for 1600MHz and
+   900mV for 800MHz, the option to pass is:
+     pnforce=10,12:8,16:0,26
+*/
+
+#define OVERRIDEPST_MAXLEN 16
+struct pst_s overridePST[OVERRIDEPST_MAXLEN];
+int overridePST_len = 0;
+static int __init pnforce_setup(char *str)
+{
+  char err = 0;
+  int i, j;
+  unsigned long t;
+
+  printk(KERN_INFO PFX "pnforce=%s\n", str);
+
+  overridePST_len = 1;
+  for ( i = 0 ; str[i] != '\0' ; i++ ) 
+    if ( str[i] == ':' )
+      overridePST_len++;
+
+  if ( overridePST_len > OVERRIDEPST_MAXLEN ) {
+    printk(KERN_INFO PFX "Too many fid/vid couples (max: %d)!\n", OVERRIDEPST_MAXLEN - 1);
+    err = 1;
+  } else
+    for ( i = 0 ; i < overridePST_len ; i++ ) {
+      t = simple_strtoul(str, &str, 10);
+      if ( *str != ',' ) {
+	printk(KERN_INFO PFX "Can't parse pnforce option!\n");
+	err = 1; break;
+      }
+      str++;
+      if ( t & INVALID_FID_MASK ) {
+	printk(KERN_INFO PFX "Invalid fid in pnforce!\n");
+	err = 1; break;
+      }
+      for ( j = 0 ; j < i ; j++ )
+	if ( overridePST[j].fid == t ) {
+	  printk(KERN_INFO PFX "Repeated fid in pnforce!\n");
+	  err = 1; break;
+	}
+      if ( err )
+	break;
+
+      overridePST[i].fid = t & FID_MASK;
+
+      t = simple_strtoul(str, &str, 10);
+      if ( (i < overridePST_len - 1 && *str != ':') || (i == overridePST_len - 1 && *str != '\0') ) {
+	printk(KERN_INFO PFX "Can't parse pnforce option!\n");
+	err = 1; break;
+      }
+      str++;
+      if ( t & INVALID_VID_MASK ) {
+	printk(KERN_INFO PFX "Invalid vid in pnforce!\n");
+	err = 1; break;
+      }
+
+      overridePST[i].vid = t & VID_MASK;
+    }
+
+  if ( err ) {
+    printk(KERN_INFO PFX "Ignoring the whole \"pnforce\" option.\n");
+    overridePST_len = 0;
+  }
+
+  return 0;
+}
+__setup("pnforce=", pnforce_setup);
+
+
+static u8 get_forced_vid(u8 fid, u8 vid) {
+  int i;
+
+  for ( i = 0 ; i < overridePST_len ; i++ )
+    if ( fid == overridePST[i].fid ) {
+      printk(KERN_INFO PFX "fid %x: overriding vid (was %x; is %x)\n", fid, vid, overridePST[i].vid);
+      return overridePST[i].vid;
+    }
+
+  return vid;
+}
+
 static int fill_powernow_table(struct powernow_k8_data *data, struct pst_s *pst, u8 maxvid)
 {
 	struct cpufreq_frequency_table *powernow_table;
@@ -585,6 +692,8 @@ static int fill_powernow_table(struct po
 	}
 
 	for (j = 0; j < data->numps; j++) {
+		pst[j].vid = get_forced_vid(pst[j].fid, pst[j].vid);
+
 		powernow_table[j].index = pst[j].fid; /* lower 8 bits */
 		powernow_table[j].index |= (pst[j].vid << 8); /* upper 8 bits */
 		powernow_table[j].frequency = find_khz_freq_from_fid(pst[j].fid);
@@ -752,6 +861,8 @@ static int powernow_k8_cpu_init_acpi(str
 			vid = (data->acpi_data.states[i].control >> VID_SHIFT) & VID_MASK;
 		}
 
+		vid = get_forced_vid(fid, vid);
+
 		dprintk("   %d : fid 0x%x, vid 0x%x\n", i, fid, vid);
 
 		powernow_table[i].index = fid; /* lower 8 bits */