diff options
| author |   Catherine Sullivan <csully@google.com> | 2021-05-17 14:08:14 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2021-05-17 15:38:40 -0700 |
| commit | f81781835f0adfae8d701545386030d223efcd6f (patch) | |
| tree | eb5a3344bb947ff88647919b7964a4c95ad266e4 | |
| parent | gve: Add NULL pointer checks when freeing irqs. (diff) | |
| download | wireguard-linux-f81781835f0adfae8d701545386030d223efcd6f.tar.xz wireguard-linux-f81781835f0adfae8d701545386030d223efcd6f.zip | |
gve: Upgrade memory barrier in poll routine
As currently written, if the driver checks for more work (via
gve_tx_poll or gve_rx_poll) before the device posts work and the
irq doorbell is not unmasked
(via iowrite32be(GVE_IRQ_ACK | GVE_IRQ_EVENT, ...)) before the device
attempts to raise an interrupt, an interrupt is lost and this could
potentially lead to the traffic being completely halted. For
example, if a tx queue has already been stopped, the driver won't get
the chance to complete work and egress will be halted.
We need a full memory barrier in the poll
routine to ensure that the irq doorbell is unmasked before the driver
checks for more work.
Fixes: f5cedc84a30d ("gve: Add transmit and receive support")
Signed-off-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David Awogbemila <awogbemila@google.com>
Acked-by: Willem de Brujin <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/google/gve/gve_main.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c index 21a5d058dab4..bbc423e93122 100644 --- a/drivers/net/ethernet/google/gve/gve_main.c +++ b/drivers/net/ethernet/google/gve/gve_main.c @@ -180,7 +180,7 @@ static int gve_napi_poll(struct napi_struct *napi, int budget) /* Double check we have no extra work. * Ensure unmask synchronizes with checking for work. */ - dma_rmb(); + mb(); if (block->tx) reschedule |= gve_tx_poll(block, -1); if (block->rx) |