RE: [PATCH] e1000e: Relax condition to trigger reset for ME workaround

[Brown, Aaron F]

> From: netdev-owner@xxxxxxxxxxxxxxx <netdev-owner@xxxxxxxxxxxxxxx> On
> Behalf Of Punit Agrawal
> Sent: Thursday, May 14, 2020 9:31 PM
> To: Kirsher, Jeffrey T <jeffrey.t.kirsher@xxxxxxxxx>
> Cc: daniel.sangorrin@xxxxxxxxxxxxx; Punit Agrawal
> <punit1.agrawal@xxxxxxxxxxxxx>; Alexander Duyck
> <alexander.h.duyck@xxxxxxxxxxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>;
> intel-wired-lan@xxxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH] e1000e: Relax condition to trigger reset for ME workaround
> 
> It's an error if the value of the RX/TX tail descriptor does not match
> what was written. The error condition is true regardless the duration
> of the interference from ME. But the driver only performs the reset if
> E1000_ICH_FWSM_PCIM2PCI_COUNT (2000) iterations of 50us delay have
> transpired. The extra condition can lead to inconsistency between the
> state of hardware as expected by the driver.
> 
> Fix this by dropping the check for number of delay iterations.
> 
> While at it, also make __ew32_prepare() static as it's not used
> anywhere else.
> 
> Signed-off-by: Punit Agrawal <punit1.agrawal@xxxxxxxxxxxxx>
> Reviewed-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
> Cc: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: intel-wired-lan@xxxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
> Hi Jeff,
> 
> If there are no further comments please consider merging the patch.
> 
> Also, should it be marked for backport to stable?
> 
> Thanks,
> Punit
> 
> RFC[0] -> v1:
> * Dropped return value for __ew32_prepare() as it's not used
> * Made __ew32_prepare() static
> * Added tags
> 
> [0] https://lkml.org/lkml/2020/5/12/20
> 
>  drivers/net/ethernet/intel/e1000e/e1000.h  |  1 -
>  drivers/net/ethernet/intel/e1000e/netdev.c | 12 +++++-------
>  2 files changed, 5 insertions(+), 8 deletions(-)
> 
Tested-by: Aaron Brown <aaron.f.brown@xxxxxxxxx>