On Fri, 2013-02-01 at 19:13 +0000, Mark Einon wrote: > On 31 January 2013 15:04, Alan Stern <[email protected]> wrote: > > On Wed, 30 Jan 2013, Mark Einon wrote: > > > >> >> > >> This patch fixes the kernel warning generated when putting an MSI > >> >> > >> MS-1727 > >> >> > >> GT740 laptop into suspend mode. The call sequence in this case > >> >> > >> calls > >> >> > >> free_irq() twice, once in pci_remove() and once then in > >> >> > >> pci_suspend(). > >> >> > > > >> >> > > You mean /first/ in pci_suspend() and /then/ in pci_remove() on the > >> >> > > already suspended devices, right? > >> >> > > >> >> > Yes, I did. The call sequence is suspend then resume. My bad. > >> > > >> > Why does the pci_suspend routine call free_irq() at all? As far as I > >> > know, it's not supposed to do that. Won't the device continue to use > >> > the same IRQ after it is resumed? > >> > >> This sounds reasonable to me - I think we could probably get rid of > >> the request_irq() call from resume, and use > >> disable_irq()/enable_irq()? > > > > Why mess around with IRQ settings at all? Just have the suspend > > routine tell the controller to stop generating them. > > > > Alan Stern > > > > I looked into doing this; using context_stop() to stop the controller running. > > However, removing the enable_irq() from pci_resume() involves not > calling ohci_enable() (as it is also the fw_card_driver.enable > function, and can't easily be modified). As this call involves a lot > of register writes and I have no devices to test, I decided against > it. > > I'll send an updated patch for consideration that merely uses a bool > to stop the irq being freed twice - crude, but it works without > changing too much code.
Hi Mark, I think what Alan means is that the suspend/resume code should just mask/unmask interrupts at the OHCI controller, via the OHCI IntEventClear/Set registers (naturally, saving the current mask and restoring it on resume). Of course, there's a lot more to do with an OHCI controller -- as you note. Like stopping running DMA contexts :) And restarting them on resume. I'd do it, but I'm buried to my eyeballs in tty right now -- not fun. I can _eventually_ do this as I need to address problems with the FW643 anyway at some point, but it's going to be a little while. In the meantime, I'm a little confused: you say you can't test this code because you have no hardware; but then how'd you trip this bug? Regards, Peter Hurley -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
