Re: [PATCH 2.6.21-rc5] MSI: read-flush MSI-X table (rev 2)

From: Chuck Ebbert
Date: Thu Mar 29 2007 - 13:26:09 EST


Mitch Williams wrote:
> This patch fixes a kernel bug which is triggered when using the
> irqbalance daemon with MSI-X hardware.
>
> Because both MSI-X interrupt messages and MSI-X table writes are posted,
> it's possible for them to cross while in-flight. This results in
> interrupts being received long after the kernel thinks they're disabled,
> and in interrupts being sent to stale vectors after rebalancing.
>
> This patch performs a read flush after writes to the MSI-X table for
> mask/unmask and rebalancing operations.
>
> This patch has been validated with (unreleased) network hardware which
> uses MSI-X.
>
> Revised with input from Eric Biederman.
>
> Signed-off-by: Mitch Williams <mitch.a.williams@xxxxxxxxx>
>

Are you going to post one for 2.6.20 as well? Some people might be
interested...


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