Re: [PATCH w-t] iwlwifi: rewrite iwl-scan.c to avoid race conditions

[Stanislaw Gruszka <sgruszka@redhat.com>]

On Wed, Sep 01, 2010 at 12:59:20PM +0200, Johannes Berg wrote:
> On Tue, 2010-08-31 at 17:00 +0200, Stanislaw Gruszka wrote:
> 
> > Scan works have now custom workqueue to allow scan functions
> > to run in parallel with other iwlwifi works, which could wait
> > for scan abort finish.
> 
> Do we really need a complete workqueue? It seems like the relevant work
> structs that really do need to be waited for from the workqueue can be
> queued with schedule_work?

Custom workqueue is not strictly needed, but it assure all works will
run short after schedule. Common workqueue can not give us such guarantees,
as other driver/subsystem can schedule own work, possibly slow, which
can block start of our work for long time.

> Shouldn't that only be a few of them anyway?

For sure abort_scan and abort_timeout works have to be scheduled on something
other than priv->workqueue. I'm queuing all scan works on priv->scan_workqueue
for consistency.

Stanislaw