On Friday 25 September 2009, Anton Vorontsov wrote: > On Fri, Sep 25, 2009 at 02:32:30PM +0200, Rafael J. Wysocki wrote: > > On Friday 25 September 2009, Alan Stern wrote: > > > On Thu, 24 Sep 2009, Anton Vorontsov wrote: > > > > > > > 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? > > > > > > > - 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. That's exactly why I suggested to do that. :-) > I'll send another patch that reworks PM stuff in the driver soon. Thanks a lot for taking care of this! Best, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
