On Monday 23 February 2009, Ingo Molnar wrote:

* Rafael J. Wysocki [off-list ref] wrote:

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Index: linux-2.6/arch/x86/kernel/apm_32.c
===================================================================

--- linux-2.6.orig/arch/x86/kernel/apm_32.c
+++ linux-2.6/arch/x86/kernel/apm_32.c

quoted

+
+	suspend_device_irqs();
 	device_power_down(PMSG_SUSPEND);
+
+	local_irq_disable();

hm, this is a very repetitive pattern, all around the various 
suspend/resume variants. Might make sense to make:

  	device_power_down(PMSG_SUSPEND);

do the irq line disabling plus the local irq disabling 
automatically. That also means it cannot be forgotten. The 
symmetric action should happen for PMSG_RESUME.

Is there ever a case where we want a different pattern?

Even if there's no such case, I prefer to call 
local_irq_disable() explicitly in here, so that it's clearly 
known where it happens to anyone reading this code.

That property can be implied in the function name:

   	device_power_down_irq_disable(PMSG_SUSPEND);

Open-coding it, if it looks the same in all the cases just 
increases the chances that someone somewhere copies them 
incorrectly.

Well, I see your point, but in that case I'd rather couple the disabling of
local interrupts on the CPU with sysdev_suspend and the disabling (or whatever
Eric would like to call that) of device interrupts with device_power_down().

Thanks,
Rafael