Messages in this thread | | | Date | Wed, 21 May 2008 13:32:10 -0600 | From | "Leonardo Chiquitto" <> | Subject | Re: [PATCH] USB: fix deadlock in HCD code |
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>> > > Used in the suspend code. Your patch is indeed correct, but I fear >> > > there might be a second bug caused by wrong calling conditions. >> > The problem in the Novell bugzilla entry was caused by the fact that the >> > OHCI irq routine was invoked with interrupts enabled, owing to a missing >> > IRQF_DISABLED flag. That bug has already been fixed in 2.6.25. >> >> That indeed is 2.6.25 kernel. I guess you are talking about commit >> 442258e2ff69 here. > > Yes. > >> If so, the reporter is definitely using the kernel >> containing this commit, and the lockups still trigger. >> >> Seems that my patch is papering over the real bug (someone enabling >> interrupts somewhere) indeed, but I can't seem to be able to find such >> codepath. > > You could try testing the interrupt-enable flag at various places > in ohci-hcd (start with finish_urb) and printing an error message if > interrupts are enabled. > > One possibility is that in an earlier call to finish_urb, > usb_hcd_giveback_urb was called with interrupts disabled and returned > with interrupts enabled. In other words, some driver's callback > routine may have enabled interrupts incorrectly.
Alan,
I am trying your suggestion right now. Lets see if it finds something.
Thanks, Leonardo
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