Messages in this thread | | | Subject | Re: [PATCH] firewire: Fix ohci free_irq() warning | From | Peter Hurley <> | Date | Fri, 01 Feb 2013 16:14:30 -0500 |
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On Fri, 2013-02-01 at 16:09 -0500, Peter Hurley wrote: > On Fri, 2013-02-01 at 19:13 +0000, Mark Einon wrote: > > On 31 January 2013 15:04, Alan Stern <stern@rowland.harvard.edu> 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.
Sorry that should read...
> 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 ^^^^^^^^ IntMaskClear/Set
by clearing/setting masterIntEnable
> 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
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