Messages in this thread | | | From | Alexander Duyck <> | Date | Wed, 14 Mar 2018 18:48:40 -0700 | Subject | Re: [PATCH 4/7] igbvf: eliminate duplicate barriers on weakly-ordered archs |
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On Tue, Mar 13, 2018 at 8:20 PM, Sinan Kaya <okaya@codeaurora.org> wrote: > Code includes wmb() followed by writel(). 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/igbvf/netdev.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/intel/igbvf/netdev.c b/drivers/net/ethernet/intel/igbvf/netdev.c > index 4214c15..fe3441b 100644 > --- a/drivers/net/ethernet/intel/igbvf/netdev.c > +++ b/drivers/net/ethernet/intel/igbvf/netdev.c > @@ -251,7 +251,7 @@ static void igbvf_alloc_rx_buffers(struct igbvf_ring *rx_ring, > * such as IA-64). > */ > wmb(); > - writel(i, adapter->hw.hw_addr + rx_ring->tail); > + writel_relaxed(i, adapter->hw.hw_addr + rx_ring->tail); > } > } >
This one missed the writel at the end of igbvf_tx_queue_adv().
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