[ofw] Filter Drivers in WinOF

[John Russo]

QLogic is seeing some issues with the current implementation of IPoIB and how it affects PnP Notifications.

Can anyone tell me why we are doing things this way or if they disagree with the following statements...

Problem:
IPoIB registers itself to handle PnP notifications in ipoib_driver.c, function ipoib_pnp_notify().  Any PnP notification other than PowerProfileChanged will cause the adapter state to become "Removed" and the IPoIB filter driver will drop it's connection.  This is in direct contradiction to MS Best Practices for filter drivers, which clearly state that filter drivers should *not* interpret PnP or Power notifications, but should instead pass these down the driver stack to the base driver which has the responsibility for actually interpreting the event.  This is similar to the WinVerbs D0 handler, where the WinVerbs *filter* driver is attempting to manage a Power notification.

Solution:
IPoIB should follow the MS Best Practices for filter drivers and stop attempting to manage the Power or PnP notifications, and allow them to pass down the driver stack

Additional:
This will become problematic during PCI rebalancing, which recall is *not* supposed to cause a teardown but instead a suspension.  IPoIB will treat the PnP rebalance notifications as "teardown" events



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John F. Russo
Engineering Manager
QLogic Corporation
780 Fifth Avenue
Suite 140
King of Prussia, PA 19406
Direct: 610-233-4866
Fax:      610-233-4777
Cell:     610-246-9903
www.qlogic.com<http://www.qlogic.com>

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