| Message ID | 1520997629-17361-2-git-send-email-okaya@codeaurora.org |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [1/7] i40e/i40evf: Eliminate duplicate barriers on weakly-ordered archs | expand |
On Tue, Mar 13, 2018 at 8:20 PM, Sinan Kaya <okaya@codeaurora.org> wrote: > Code includes wmb() followed by writel() in multiple places. writel() > already has a barrier on some architectures like arm64. > > This ends up CPU observing two barriers back to back before executing the > register write. > > Since code already has an explicit barrier call, changing writel() to > writel_relaxed(). > > Signed-off-by: Sinan Kaya <okaya@codeaurora.org> In this patch you missed the writel at the end of ixgbe_tx_map.
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index 0da5aa2..35ca1d8 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -1692,7 +1692,7 @@ void ixgbe_alloc_rx_buffers(struct ixgbe_ring *rx_ring, u16 cleaned_count) * such as IA-64). */ wmb(); - writel(i, rx_ring->tail); + writel_relaxed(i, rx_ring->tail); } } @@ -2453,7 +2453,7 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector, * know there are new descriptors to fetch. */ wmb(); - writel(ring->next_to_use, ring->tail); + writel_relaxed(ring->next_to_use, ring->tail); xdp_do_flush_map(); } @@ -10014,7 +10014,7 @@ static void ixgbe_xdp_flush(struct net_device *dev) * are new descriptors to fetch. */ wmb(); - writel(ring->next_to_use, ring->tail); + writel_relaxed(ring->next_to_use, ring->tail); return; }
Code includes wmb() followed by writel() in multiple places. writel() already has a barrier on some architectures like arm64. This ends up CPU observing two barriers back to back before executing the register write. Since code already has an explicit barrier call, changing writel() to writel_relaxed(). Signed-off-by: Sinan Kaya <okaya@codeaurora.org> --- drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)