[CPUFREQ] Longhaul - Add VT8235 support
I don't know why it is working and how, but it is working. On my
Epia transition time is by default set to 100us. I'm changing it to
200us. After that I can change frequency from min (x4.0) to max (x7.5)
without lockup. Many times.
There is a paranoid check at a beginning of a patch. Probably dead
code, but I don't have better ideas for CL10000 case at the moment.
Only way to to detect broken chip seems to be looking in log for
spurious interrupts.
Signed-off-by: Rafal Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
diff --git a/arch/i386/kernel/cpu/cpufreq/longhaul.c b/arch/i386/kernel/cpu/cpufreq/longhaul.c
index 8b5ad30..98fbe28 100644
--- a/arch/i386/kernel/cpu/cpufreq/longhaul.c
+++ b/arch/i386/kernel/cpu/cpufreq/longhaul.c
@@ -56,6 +56,7 @@
/* Flags */
#define USE_ACPI_C3 (1 << 1)
#define USE_NORTHBRIDGE (1 << 2)
+#define USE_VT8235 (1 << 3)
static int cpu_model;
static unsigned int numscales=16;
@@ -544,20 +545,50 @@
if (dev != NULL) {
/* Enable access to port 0x22 */
pci_read_config_byte(dev, reg, &pci_cmd);
- if ( !(pci_cmd & 1<<7) ) {
+ if (!(pci_cmd & 1<<7)) {
pci_cmd |= 1<<7;
pci_write_config_byte(dev, reg, pci_cmd);
+ pci_read_config_byte(dev, reg, &pci_cmd);
+ if (!(pci_cmd & 1<<7)) {
+ printk(KERN_ERR PFX
+ "Can't enable access to port 0x22.\n");
+ return 0;
+ }
}
return 1;
}
return 0;
}
+static int longhaul_setup_vt8235(void)
+{
+ struct pci_dev *dev;
+ u8 pci_cmd;
+
+ /* Find VT8235 southbridge */
+ dev = pci_find_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235, NULL);
+ if (dev != NULL) {
+ /* Set transition time to max */
+ pci_read_config_byte(dev, 0xec, &pci_cmd);
+ pci_cmd &= ~(1 << 2);
+ pci_write_config_byte(dev, 0xec, pci_cmd);
+ pci_read_config_byte(dev, 0xe4, &pci_cmd);
+ pci_cmd &= ~(1 << 7);
+ pci_write_config_byte(dev, 0xe4, pci_cmd);
+ pci_read_config_byte(dev, 0xe5, &pci_cmd);
+ pci_cmd |= 1 << 7;
+ pci_write_config_byte(dev, 0xe5, pci_cmd);
+ return 1;
+ }
+ return 0;
+}
+
static int __init longhaul_cpu_init(struct cpufreq_policy *policy)
{
struct cpuinfo_x86 *c = cpu_data;
char *cpuname=NULL;
int ret;
+ int vt8235_present;
/* Check what we have on this motherboard */
switch (c->x86_model) {
@@ -641,12 +672,16 @@
break;
};
+ /* Doesn't hurt */
+ vt8235_present = longhaul_setup_vt8235();
+
/* Find ACPI data for processor */
- acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX,
- &longhaul_walk_callback, NULL, (void *)&pr);
+ acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX, &longhaul_walk_callback,
+ NULL, (void *)&pr);
/* Check ACPI support for C3 state */
- if ((pr != NULL) && (longhaul_version == TYPE_POWERSAVER)) {
+ if (pr != NULL && longhaul_version == TYPE_POWERSAVER) {
cx = &pr->power.states[ACPI_STATE_C3];
if (cx->address > 0 && cx->latency <= 1000) {
longhaul_flags |= USE_ACPI_C3;
@@ -658,8 +693,11 @@
longhaul_flags |= USE_NORTHBRIDGE;
goto print_support_type;
}
-
- /* No ACPI C3 or we can't use it */
+ /* Use VT8235 southbridge if present */
+ if (longhaul_version == TYPE_POWERSAVER && vt8235_present) {
+ longhaul_flags |= USE_VT8235;
+ goto print_support_type;
+ }
/* Check ACPI support for bus master arbiter disable */
if ((pr == NULL) || !(pr->flags.bm_control)) {
printk(KERN_ERR PFX
@@ -668,18 +706,18 @@
}
print_support_type:
- if (!(longhaul_flags & USE_NORTHBRIDGE)) {
- printk (KERN_INFO PFX "Using ACPI support.\n");
- } else {
+ if (longhaul_flags & USE_NORTHBRIDGE)
printk (KERN_INFO PFX "Using northbridge support.\n");
- }
+ else if (longhaul_flags & USE_VT8235)
+ printk (KERN_INFO PFX "Using VT8235 support.\n");
+ else
+ printk (KERN_INFO PFX "Using ACPI support.\n");
ret = longhaul_get_ranges();
if (ret != 0)
return ret;
- if ((longhaul_version==TYPE_LONGHAUL_V2 || longhaul_version==TYPE_POWERSAVER) &&
- (scale_voltage != 0))
+ if ((longhaul_version != TYPE_LONGHAUL_V1) && (scale_voltage != 0))
longhaul_setup_voltagescaling();
policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
