[net-next 07/10] i40e: stop using cmpxchg flow in i40e_set_priv_flags()
flat view
From: Jeff Kirsher <hidden>
Date: 2018-03-26 21:40:36
Subsystem:
intel ethernet drivers, networking drivers, the rest · Maintainers:
Tony Nguyen, Przemek Kitszel, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Jacob Keller <jacob.e.keller@intel.com> Now that the only places which modify flags are either (a) during initialization prior to creating a netdevice, or (b) while holding the rtnl lock, we no longer need the cmpxchg64 call in i40e_set_priv_flags. Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Tested-by: Andrew Bowers <redacted> Signed-off-by: Jeff Kirsher <redacted> --- drivers/net/ethernet/intel/i40e/i40e_ethtool.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
index 2a9c93091e3d..b974482ff630 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c@@ -4436,21 +4436,12 @@ static int i40e_set_priv_flags(struct net_device *dev, u32 flags) } } - /* Compare and exchange the new flags into place. If we failed, that - * is if cmpxchg returns anything but the old value, this means that - * something else has modified the flags variable since we copied it - * originally. We'll just punt with an error and log something in the - * message buffer. - * - * This is the point of no return for this function. We need to have - * checked any discrepancies or misconfigurations and returned - * EOPNOTSUPP before updating pf->flags here. + /* Now that we've checked to ensure that the new flags are valid, load + * them into place. Since we only modify flags either (a) during + * initialization or (b) while holding the RTNL lock, we don't need + * anything fancy here. */ - if (cmpxchg64(&pf->flags, orig_flags, new_flags) != orig_flags) { - dev_warn(&pf->pdev->dev, - "Unable to update pf->flags as it was modified by another thread...\n"); - return -EAGAIN; - } + pf->flags = new_flags; /* Process any additional changes needed as a result of flag changes. * The changed_flags value reflects the list of bits that were
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2.14.3