static void bbswitch_off(void) {
if (is_card_disabled())
return;
// to prevent the system from possibly locking up, don't disable the device
// if it's still in use by a driver (i.e. nouveau or nvidia)
if (dis_dev->driver) {
pr_warn("device %s is in use by driver '%s', refusing OFF\n",
dev_name(&dis_dev->dev), dis_dev->driver->name);
return;
}
pr_info("disabling discrete graphics\n");
if (bbswitch_optimus_dsm()) {
pr_warn("Optimus ACPI call failed, the device is not disabled\n");
return;
}
pci_save_state(dis_dev);
pci_clear_master(dis_dev);
pci_disable_device(dis_dev);
pci_set_power_state(dis_dev, PCI_D3cold);
if (bbswitch_acpi_off())
pr_warn("The discrete card could not be disabled by a _DSM call\n");
}
static int bbswitch_pm_handler(struct notifier_block *nbp,
unsigned long event_type, void *p) {
switch (event_type) {
case PM_HIBERNATION_PREPARE:
case PM_SUSPEND_PREPARE:
dis_dev_get();
dis_before_suspend_disabled = is_card_disabled();
// enable the device before suspend to avoid the PCI config space from
// being saved incorrectly
if (dis_before_suspend_disabled)
bbswitch_on();
dis_dev_put();
break;
case PM_POST_HIBERNATION:
case PM_POST_SUSPEND:
case PM_POST_RESTORE:
// after suspend, the card is on, but if it was off before suspend,
// disable it again
if (dis_before_suspend_disabled) {
dis_dev_get();
bbswitch_off();
dis_dev_put();
}
break;
case PM_RESTORE_PREPARE:
// deliberately don't do anything as it does not occur before suspend
// nor hibernate, but before restoring a saved image. In that case,
// either PM_POST_HIBERNATION or PM_POST_RESTORE will be called
break;
}
return 0;
}
static void bbswitch_off(void) {
if (is_card_disabled())
return;
// to prevent the system from possibly locking up, don't disable the device
// if it's still in use by a driver (i.e. nouveau or nvidia)
if (dis_dev->driver) {
printk(KERN_WARNING "bbswitch: device %s is in use by driver '%s', "
"refusing OFF\n", dev_name(&dis_dev->dev), dis_dev->driver->name);
return;
}
printk(KERN_INFO "bbswitch: disabling discrete graphics\n");
if (dsm_type == DSM_TYPE_OPTIMUS && bbswitch_optimus_dsm()) {
printk(KERN_WARNING "bbswitch: ACPI call failed, the device is not"
" disabled\n");
return;
}
pci_save_state(dis_dev);
pci_clear_master(dis_dev);
pci_disable_device(dis_dev);
pci_set_power_state(dis_dev, PCI_D3hot);
if (bbswitch_acpi_off())
printk(KERN_WARNING "bbswitch: The discrete card could not be disabled"
" by a _DSM call\n");
}
static int bbswitch_proc_show(struct seq_file *seqfp, void *p) {
// show the card state. Example output: 0000:01:00:00 ON
dis_dev_get();
seq_printf(seqfp, "%s %s\n", dev_name(&dis_dev->dev),
is_card_disabled() ? "OFF" : "ON");
dis_dev_put();
return 0;
}
static int __init bbswitch_init(void) {
struct proc_dir_entry *acpi_entry;
struct pci_dev *pdev = NULL;
int class = PCI_CLASS_DISPLAY_VGA << 8;
while ((pdev = pci_get_class(class, pdev)) != NULL) {
struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_handle handle;
handle = DEVICE_ACPI_HANDLE(&pdev->dev);
if (!handle)
continue;
if (pdev->vendor != PCI_VENDOR_ID_INTEL) {
dis_dev = pdev;
dis_handle = handle;
acpi_get_name(handle, ACPI_FULL_PATHNAME, &buf);
printk(KERN_INFO "bbswitch: Found discrete VGA device %s: %s\n",
dev_name(&pdev->dev), (char *)buf.pointer);
}
kfree(buf.pointer);
}
if (dis_dev == NULL) {
printk(KERN_ERR "bbswitch: No discrete VGA device found\n");
return -ENODEV;
}
if (has_dsm_func(acpi_optimus_dsm_muid, 0x100, 0x1A)) {
dsm_type = DSM_TYPE_OPTIMUS;
printk(KERN_INFO "bbswitch: detected an Optimus _DSM function\n");
} else if (has_dsm_func(acpi_nvidia_dsm_muid, 0x102, 0x3)) {
dsm_type = DSM_TYPE_NVIDIA;
printk(KERN_INFO "bbswitch: detected a nVidia _DSM function\n");
} else {
printk(KERN_ERR "bbswitch: No suitable _DSM call found.\n");
return -ENODEV;
}
acpi_entry = create_proc_entry("bbswitch", 0660, acpi_root_dir);
if (acpi_entry == NULL) {
printk(KERN_ERR "bbswitch: Couldn't create proc entry\n");
return -ENOMEM;
}
printk(KERN_INFO "bbswitch: Succesfully loaded. Discrete card %s is %s\n",
dev_name(&dis_dev->dev), is_card_disabled() ? "off" : "on");
acpi_entry->write_proc = bbswitch_write;
acpi_entry->read_proc = bbswitch_read;
nb.notifier_call = &bbswitch_pm_handler;
register_pm_notifier(&nb);
return 0;
}
static void bbswitch_on(void) {
if (!is_card_disabled())
return;
pr_info("enabling discrete graphics\n");
if (bbswitch_acpi_on())
pr_warn("The discrete card could not be enabled by a _DSM call\n");
pci_set_power_state(dis_dev, PCI_D0);
pci_restore_state(dis_dev);
if (pci_enable_device(dis_dev))
pr_warn("failed to enable %s\n", dev_name(&dis_dev->dev));
pci_set_master(dis_dev);
}
static void bbswitch_on(void) {
if (!is_card_disabled())
return;
printk(KERN_INFO "bbswitch: enabling discrete graphics\n");
if (bbswitch_acpi_on())
printk(KERN_WARNING "bbswitch: The discrete card could not be enabled"
" by a _DSM call\n");
pci_set_power_state(dis_dev, PCI_D0);
pci_restore_state(dis_dev);
if (pci_enable_device(dis_dev))
printk(KERN_WARNING "bbswitch: failed to enable %s\n",
dev_name(&dis_dev->dev));
pci_set_master(dis_dev);
}
static void __exit bbswitch_exit(void) {
remove_proc_entry("bbswitch", acpi_root_dir);
dis_dev_get();
if (unload_state == CARD_ON)
bbswitch_on();
else if (unload_state == CARD_OFF)
bbswitch_off();
pr_info("Unloaded. Discrete card %s is %s\n",
dev_name(&dis_dev->dev), is_card_disabled() ? "off" : "on");
dis_dev_put();
if (nb.notifier_call)
unregister_pm_notifier(&nb);
}
static void bbswitch_off(void) {
if (is_card_disabled())
return;
// to prevent the system from possibly locking up, don't disable the device
// if it's still in use by a driver (i.e. nouveau or nvidia)
if (dis_dev->driver) {
pr_warn("device %s is in use by driver '%s', refusing OFF\n",
dev_name(&dis_dev->dev), dis_dev->driver->name);
return;
}
pr_info("disabling discrete graphics\n");
if (bbswitch_optimus_dsm()) {
pr_warn("Optimus ACPI call failed, the device is not disabled\n");
return;
}
pci_save_state(dis_dev);
pci_clear_master(dis_dev);
pci_disable_device(dis_dev);
do {
struct acpi_device *ad = NULL;
int r;
r = acpi_bus_get_device(dis_handle, &ad);
if (r || !ad) {
pr_warn("Cannot get ACPI device for PCI device\n");
break;
}
if (ad->power.state == ACPI_STATE_UNKNOWN) {
pr_debug("ACPI power state is unknown, forcing D0\n");
ad->power.state = ACPI_STATE_D0;
}
} while (0);
pci_set_power_state(dis_dev, PCI_D3cold);
if (bbswitch_acpi_off())
pr_warn("The discrete card could not be disabled by a _DSM call\n");
}
static int __init bbswitch_init(void) {
struct proc_dir_entry *acpi_entry;
struct pci_dev *pdev = NULL;
acpi_handle igd_handle = NULL;
pr_info("version %s\n", BBSWITCH_VERSION);
while ((pdev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, pdev)) != NULL) {
struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_handle handle;
int pci_class = pdev->class >> 8;
if (pci_class != PCI_CLASS_DISPLAY_VGA &&
pci_class != PCI_CLASS_DISPLAY_3D)
continue;
handle = DEVICE_ACPI_HANDLE(&pdev->dev);
if (!handle) {
pr_warn("cannot find ACPI handle for VGA device %s\n",
dev_name(&pdev->dev));
continue;
}
acpi_get_name(handle, ACPI_FULL_PATHNAME, &buf);
if (pdev->vendor == PCI_VENDOR_ID_INTEL) {
igd_handle = handle;
pr_info("Found integrated VGA device %s: %s\n",
dev_name(&pdev->dev), (char *)buf.pointer);
} else {
dis_dev = pdev;
dis_handle = handle;
pr_info("Found discrete VGA device %s: %s\n",
dev_name(&pdev->dev), (char *)buf.pointer);
}
kfree(buf.pointer);
}
if (dis_dev == NULL) {
pr_err("No discrete VGA device found\n");
return -ENODEV;
}
if (!skip_optimus_dsm &&
has_dsm_func(acpi_optimus_dsm_muid, 0x100, 0x1A)) {
dsm_type = DSM_TYPE_OPTIMUS;
pr_info("detected an Optimus _DSM function\n");
} else if (has_dsm_func(acpi_nvidia_dsm_muid, 0x102, 0x3)) {
dsm_type = DSM_TYPE_NVIDIA;
pr_info("detected a nVidia _DSM function\n");
} else {
/* At least two Acer machines are known to use the intel ACPI handle
* with the legacy nvidia DSM */
dis_handle = igd_handle;
if (dis_handle && has_dsm_func(acpi_nvidia_dsm_muid, 0x102, 0x3)) {
dsm_type = DSM_TYPE_NVIDIA;
pr_info("detected a nVidia _DSM function on the"
" integrated video card\n");
} else {
pr_err("No suitable _DSM call found.\n");
return -ENODEV;
}
}
acpi_entry = proc_create("bbswitch", 0664, acpi_root_dir, &bbswitch_fops);
if (acpi_entry == NULL) {
pr_err("Couldn't create proc entry\n");
return -ENOMEM;
}
dis_dev_get();
if (!is_card_disabled()) {
/* We think the card is enabled, so ensure the kernel does as well */
if (pci_enable_device(dis_dev))
pr_warn("failed to enable %s\n", dev_name(&dis_dev->dev));
}
if (load_state == CARD_ON)
bbswitch_on();
else if (load_state == CARD_OFF)
bbswitch_off();
pr_info("Succesfully loaded. Discrete card %s is %s\n",
dev_name(&dis_dev->dev), is_card_disabled() ? "off" : "on");
dis_dev_put();
register_pm_notifier(&nb);
return 0;
}
static int bbswitch_read(char *page, char **start, off_t off,
int count, int *eof, void *data) {
// show the card state. Example output: 0000:01:00:00 ON
return snprintf(page, count, "%s %s\n", dev_name(&dis_dev->dev),
is_card_disabled() ? "OFF" : "ON");
}