RE: [next-queue PATCH v2 1/2] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

["Brown, Aaron F" <aaron.f.brown@intel.com>]

> From: netdev-owner@vger.kernel.org <netdev-owner@vger.kernel.org>
> On Behalf Of Alexander Duyck
> Sent: Friday, October 11, 2019 8:35 AM
> To: alexander.h.duyck@linux.intel.com; intel-wired-lan@lists.osuosl.org;
> Kirsher, Jeffrey T <jeffrey.t.kirsher@intel.com>
> Cc: netdev@vger.kernel.org; zdai@us.ibm.com; zdai@linux.vnet.ibm.com
> Subject: [next-queue PATCH v2 1/2] e1000e: Use rtnl_lock to prevent race
> conditions between net and pci/pm
> 
> From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> 
> This patch is meant to address possible race conditions that can exist
> between network configuration and power management. A similar issue was
> fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
> netif_device_detach").
> 
> In addition it consolidates the code so that the PCI error handling code
> will essentially perform the power management freeze on the device prior to
> attempting a reset, and will thaw the device afterwards if that is what it
> is planning to do. Otherwise when we call close on the interface it should
> see it is detached and not attempt to call the logic to down the interface
> and free the IRQs again.
> 
> >From what I can tell the check that was adding the check for
> __E1000_DOWN
> in e1000e_close was added when runtime power management was added.
> However
> it should not be relevant for us as we perform a call to
> pm_runtime_get_sync before we call e1000_down/free_irq so it should
> always
> be back up before we call into this anyway.
> 
> Reported-by: Morumuri Srivalli <smorumu1@in.ibm.com>
> Tested-by: David Dai <zdai@linux.vnet.ibm.com>
> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> ---
>  drivers/net/ethernet/intel/e1000e/netdev.c |   68 ++++++++++++++---------
> -----
>  1 file changed, 35 insertions(+), 33 deletions(-)

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