Re: [PATCH] usb, ehci: Avoid deadlock of ehci->lock by disabling interrupts

2012-08-01 Thread Don Zickus
On Wed, Aug 01, 2012 at 10:42:37AM -0400, Alan Stern wrote: > On Tue, 31 Jul 2012, Don Zickus wrote: > > > We ran into an interesting deadlock on RHEL-5 (2.6.18) that I believe > > still appiles to the current kernel involving the ehci->lock. > > > > CPU A: > > submits a bulk transfer urb > > ehc

Re: [PATCH] usb, ehci: Avoid deadlock of ehci->lock by disabling interrupts

2012-08-01 Thread Alan Stern
On Tue, 31 Jul 2012, Don Zickus wrote: > We ran into an interesting deadlock on RHEL-5 (2.6.18) that I believe > still appiles to the current kernel involving the ehci->lock. > > CPU A: > submits a bulk transfer urb > ehci_urb_enqueue calls submit_async > submit_async blocks on ehci->lock with ir

[PATCH] usb, ehci: Avoid deadlock of ehci->lock by disabling interrupts

2012-07-31 Thread Don Zickus
We ran into an interesting deadlock on RHEL-5 (2.6.18) that I believe still appiles to the current kernel involving the ehci->lock. CPU A: submits a bulk transfer urb ehci_urb_enqueue calls submit_async submit_async blocks on ehci->lock with irq disabled (the result of spin_lock_irqsave) for CPU B