shark/bbswitch-g14
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bbswitch: If necessary, enable card before suspend and disable after

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This commit is contained in:
Lekensteyn 2011-12-11 23:41:02 +01:00
parent 41da066752
commit f7e6dd9741
1 changed files with 35 additions and 0 deletions
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35
bbswitch.c
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@ -9,6 +9,7 @@
#include <linux/acpi.h>
#include <linux/module.h>
#include <asm/uaccess.h>
#include <linux/suspend.h>
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Toggle the discrete graphics card");
@ -23,6 +24,11 @@ static const char acpi_optimus_dsm_muid[] = {
static struct pci_dev *dis_dev;
static acpi_handle dis_handle;
/* used for keeping the PM event handler */
static struct notifier_block nb;
/* whether the card was off before suspend or not; on: 0, off: 1 */
int dis_before_suspend_disabled;
/* shamelessly taken from nouveau_acpi.c */
static int acpi_optimus_dsm(acpi_handle handle, int func, char *args,
uint32_t *result) {
@ -156,6 +162,29 @@ static int bbswitch_read(char *page, char **start, off_t off,
is_card_disabled() ? "OFF" : "ON");
}
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_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();
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)
bbswitch_off();
break;
}
return 0;
}
static int __init bbswitch_init(void) {
struct proc_dir_entry *acpi_entry;
struct pci_dev *pdev = NULL;
@ -196,11 +225,17 @@ static int __init bbswitch_init(void) {
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 __exit bbswitch_exit(void) {
remove_proc_entry("bbswitch", acpi_root_dir);
if (nb.notifier_call)
unregister_pm_notifier(&nb);
}
module_init(bbswitch_init);