acpi_os_stall() is used in two ways. The typical way is what triggered this e-mail thread. It implements the AML "Stall()" operator, and is called with interrupts enabled with durations <= 100 usec. So one would expect it to be identical to udelay(). The exception case is when ACPICA calls it with interrupts off and huge durations when we wrote the poweroff or sleep register, yet we find outselves still running... Apparently akpm added touch_nmi_watchdog() to keep the watchdog from firing in this exception case. Is it useful to have the watchdog running when we are waiting for firmware to poweroff the machine? If no, maybe we should turn it off as part of the shutdown process rather than using yet another invocation of touch_nmi_watchdog()? Is calling delay() with IRQs disabled the best thing we can do after we ask the firmware to cut power and it takes a long time? thanks, Len Brown, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
