On Fri, Sep 25, 2009 at 02:32:30PM +0200, Rafael J. Wysocki wrote:

On Friday 25 September 2009, Alan Stern wrote:

quoted

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.

Well, it is necessary if 3c59x really throws spurious interrupts
upon suspend (i.e. after pci_disable_device(pdev)). My first though
was to just remove free/request_irq stuff, but then I could introduce
a regression if 3c59x really throws unexpected IRQs and 3c59x was
the only user of a PCI IRQ (in that case free_irq() would actually
help).

Anton, have you tried without that?

Yes, and there wasn't any issues for 3x59x I have. Alan raised a very
good point, and converting to dev_pm_opsas as you've suggested would
solve it in a nice way, since if we use the dev_pm_ops, PCI core
will disable the device in _noirq suspend, after we quiesced the
chip itself.

I'll send another patch that reworks PM stuff in the driver soon.

Thanks,

-- 
Anton Vorontsov
email: cbouatmailru@gmail.com
irc://irc.freenode.net/bd2