svn commit: r357288 - head/sys/dev/usb/wlan

[Ian Lepore]

On Thu, 2020-01-30 at 09:41 +0000, Hans Petter Selasky wrote:
> Author: hselasky
> Date: Thu Jan 30 09:41:48 2020
> New Revision: 357288
> URL: https://svnweb.freebsd.org/changeset/base/357288
> 
> Log:
>   Widen EPOCH(9) usage in USB WLAN drivers.
>   
>   This patch should unbreak the USB WLAN drivers after r357004.
>   
>   Pointy hat:	glebius@
>   Sponsored by:	Mellanox Technologies
> 
> Modified:
>   head/sys/dev/usb/wlan/if_rum.c
>   head/sys/dev/usb/wlan/if_run.c
>   head/sys/dev/usb/wlan/if_uath.c
>   head/sys/dev/usb/wlan/if_upgt.c
>   head/sys/dev/usb/wlan/if_ural.c
>   head/sys/dev/usb/wlan/if_urtw.c
>   head/sys/dev/usb/wlan/if_zyd.c
> 

This is another piece of evidence illustratitng what a bad idea it was
to try to handle network interrupts as some sort of special case in the
wrong layer of the OS.  Network drivers know who they are and can do
the right thing.  The interrupt dispatching code can only guess at
what's going on by using flags that were intended for a whole other
purpose.

We now how multiple demonstrations of the fact that those flags cannot
reliably be used as an indication of whether network packets are going
to be handled during the interrupt or not.

-- Ian