[Jaunty] [Karmic] Fix hostap interrupt handler oops on bootup

Stefan Bader stefan.bader at canonical.com
Wed Aug 19 15:41:43 UTC 2009

Colin Ian King wrote:
> https://bugs.launchpad.net/ubuntu/+bug/254837
> SRU Justification:
> Impact: Booting with the Senao NL-2511CD (PRISM II compatible) wireless
> card can generate a kernel oops in the hostap interrupt handler.
> Spurious shared interrupts or early probing interrupts can cause the
> hostap interrupt handler to oops before the driver has fully configured
> the IO base port addresses. In some cases the oops can be because
> the hardware shares an interrupt line, on other cases it is due to a
> race condition between probing for the hardware and configuring
> the IO base port. The latter occurs because the probing is required to
> determine the hardware port address which is only determined when the
> probe can interrupt the hardware (catch 22).
> Fix: This patch catches this pre-configured condition in the interrupt
> handler to avoid the oops.
> Testcase: Without the patch a kernel oops occurs on boot when the card
> is installed. With the patch, there is no kernel oops and the wireless
> card works.
> I originally started debugging this with a user on a Jaunty kernel, and
> now they have moved to Karmic. This patch will has been tested on Karmic
> by Dan Taylor Jr. and the patch will fix the problem for Jaunty too,
> c.f. https://bugs.launchpad.net/ubuntu/+bug/254837/comments/56
> Attached: The patch.
Has this been submitted upstream?


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