On Wednesday 05 December 2007, Alan Stern wrote: > > In regard to: > > http://bugzilla.kernel.org/show_bug.cgi?id=9335 > > The problem appears to be that ohci-hcd (and also ehci-hcd) calls > spin_lock() in its IRQ handler instead of spin_lock_irqsave(). A > deadlock occurs because interrupts are not disabled while the handler > runs. > > The patch attached to comment #11 changes those calls. Do you agree > this is the right way to solve the problem?
Of all the HCDs in drivers/usb/host, only uhci uses the irqsave/restore variant. That's because the IRQ handlers were supposed to be registered in the "leave IRQs disabled" (IRQF_DISABLED) mode. Updating usb_add_hcd to use IRQF_DISABLED would restore that original assumption. I'm not sure when that flag (or its predecessor) got lost, but that change is surely the root cause of these problems. Do you recall why/when that flag got dropped? - Dave - To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
