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| author | Björn Töpel <bjorn.topel@intel.com> | 2020-12-11 17:57:12 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-12-30 13:53:56 +0300 |
| commit | bc79bf6c581cde11213a2119bcf7dc2c59cd22ec (patch) | |
| tree | 2258061f58f5bfa345bb4aafb62578241f1083d3 /drivers/net/ethernet | |
| parent | 0c3d87fa50a6c7bf68806b7406c165c5e18d3737 (diff) | |
| download | linux-bc79bf6c581cde11213a2119bcf7dc2c59cd22ec.tar.xz | |
i40e, xsk: clear the status bits for the next_to_use descriptor
[ Upstream commit 64050b5b8706d304ba647591b06e1eddc55e8bd9 ]
On the Rx side, the next_to_use index points to the next item in the
HW ring to be refilled/allocated, and next_to_clean points to the next
item to potentially be processed.
When the HW Rx ring is fully refilled, i.e. no packets has been
processed, the next_to_use will be next_to_clean - 1. When the ring is
fully processed next_to_clean will be equal to next_to_use. The latter
case is where a bug is triggered.
If the next_to_use bits are not cleared, and the "fully processed"
state is entered, a stale descriptor can be processed.
The skb-path correctly clear the status bit for the next_to_use
descriptor, but the AF_XDP zero-copy path did not do that.
This change adds the status bits clearing of the next_to_use
descriptor.
Fixes: 3b4f0b66c2b3 ("i40e, xsk: Migrate to new MEM_TYPE_XSK_BUFF_POOL")
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/net/ethernet')
| -rw-r--r-- | drivers/net/ethernet/intel/i40e/i40e_xsk.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c index 567fd67e900e..e402c62eb313 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c @@ -219,8 +219,11 @@ bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count) } while (count); no_buffers: - if (rx_ring->next_to_use != ntu) + if (rx_ring->next_to_use != ntu) { + /* clear the status bits for the next_to_use descriptor */ + rx_desc->wb.qword1.status_error_len = 0; i40e_release_rx_desc(rx_ring, ntu); + } return ok; } |