Re: [linux-pm] [PATCH] 3c59x: Get rid of "Trying to free already-free IRQ"
From: Rafael J. Wysocki <hidden>
Date: 2009-09-25 12:31:31
On Friday 25 September 2009, Alan Stern wrote:
On Thu, 24 Sep 2009, Anton Vorontsov wrote:quoted
Though, there are few other issues with suspend/resume in this driver. The intention of calling free_irq() in suspend() was to avoid any possible spurious interrupts (see commit 5b039e681b8c5f30aac9cc04385 "3c59x PM fixes"). But, - On resume, the driver was requesting IRQ just after pci_set_master(), but before vortex_up() (which actually resets 3c59x chips).Shouldn't it be possible to reset the chip (or at least prevent it from generating spurious IRQs) during the early-resume phase?quoted
- Issuing free_irq() on a shared IRQ doesn't guarantee that a buggy HW won't trigger spurious interrupts in another driver that requested the same interrupt. So, if we want to protect from unexpected interrupts, then on suspend we should issue disable_irq(), not free_irq().What if some other device shares the IRQ and still relies on receiving interrupts when this code runs? Won't disable_irq() mess up the other device?
Ah, I overlooked the disable_irq()/enable_irq() part, which is not really necessary anyway. Anton, have you tried without that? Rafael