RE: [Intel-wired-lan] [PATCH net-queue 3/3] e1000e: Avoid missed interrupts following ICR read.

[Brown, Aaron F]

> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@xxxxxxxxxx] On
> Behalf Of Benjamin Poirier
> Sent: Wednesday, February 7, 2018 10:47 PM
> To: Kirsher, Jeffrey T <jeffrey.t.kirsher@xxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx; intel-wired-lan@xxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Subject: [Intel-wired-lan] [PATCH net-queue 3/3] e1000e: Avoid missed
> interrupts following ICR read.
> 
> The 82574 specification update errata 12 states that interrupts may be
> missed if ICR is read while INT_ASSERTED is not set. Avoid that problem by
> setting all bits related to events that can trigger the Other interrupt in
> IMS.
> 
> The Other interrupt is raised for such events regardless of whether or not
> they are set in IMS. However, only when they are set is the INT_ASSERTED
> bit also set in ICR.
> 
> By doing this, we ensure that INT_ASSERTED is always set when we read ICR
> in e1000_msix_other() and steer clear of the errata. This also ensures that
> ICR will automatically be cleared on read, therefore we no longer need to
> clear bits explicitly.
> 
> Signed-off-by: Benjamin Poirier <bpoirier@xxxxxxxx>
> ---
>  drivers/net/ethernet/intel/e1000e/defines.h | 21
> ++++++++++++++++++++-
>  drivers/net/ethernet/intel/e1000e/netdev.c  | 11 ++++-------
>  2 files changed, 24 insertions(+), 8 deletions(-)
> 

Tested-by: Aaron Brown <aaron.f.brown@xxxxxxxxx>