On 01/11/2012 04:08 PM, Gerd Hoffmann wrote:
+void qemu_system_suspend_request(qemu_irq wake_irq)
+{
+ if (suspend_wake_irq != NULL) {
+ return;
+ }
+ cpu_stop_current();
+ qemu_notify_event();
+ suspend_wake_irq = wake_irq;
+}
+
+void qemu_system_wakeup_request(void)
+{
+ if (suspend_wake_irq == NULL) {
+ return;
+ }
+ reset_requested = 1;
+ qemu_irq_raise(suspend_wake_irq);
+ suspend_wake_irq = NULL;
+}
The code in acpi.c is confusing, but it seems to me that IRQ is raised
when the system _enters_ S3. See especially xen-all.c. It would be
lowered by acpi_pm1_cnt_reset when the reset actually happens on the
next main loop iteration. However, acpi_pm1_cnt_reset has never been
called since its introduction in commit eaba51c (acpi, acpi_piix,
vt82c686: factor out PM1_CNT logic, 2011-03-25).
Overall, it seems to me that with your new infrastructure a global
Notifier would be a better fit than a qemu_irq that the board would have
to pass all the way. A notifier would also remove the ugly Xen special
casing. However, this can be done separately.
Paolo
