diff mbox series

[net,v2,1/8] ice: respect netif readiness in AF_XDP ZC related ndo's

Message ID 20240729200716.681496-2-anthony.l.nguyen@intel.com (mailing list archive)
State Accepted
Commit ec145a18687fec8dd97eeb4f30057fa4debef577
Delegated to: Netdev Maintainers
Headers show
Series ice: fix AF_XDP ZC timeout and concurrency issues | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 42 this patch: 42
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 9 of 9 maintainers
netdev/build_clang success Errors and warnings before: 43 this patch: 43
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 43 this patch: 43
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 18 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 18 this patch: 18
netdev/source_inline success Was 0 now: 0
netdev/contest warning net-next-2024-07-30--03-00 (tests: 675)

Commit Message

Tony Nguyen July 29, 2024, 8:07 p.m. UTC 
From: Michal Kubiak <michal.kubiak@intel.com>

Address a scenario in which XSK ZC Tx produces descriptors to XDP Tx
ring when link is either not yet fully initialized or process of
stopping the netdev has already started. To avoid this, add checks
against carrier readiness in ice_xsk_wakeup() and in ice_xmit_zc().
One could argue that bailing out early in ice_xsk_wakeup() would be
sufficient but given the fact that we produce Tx descriptors on behalf
of NAPI that is triggered for Rx traffic, the latter is also needed.

Bringing link up is an asynchronous event executed within
ice_service_task so even though interface has been brought up there is
still a time frame where link is not yet ok.

Without this patch, when AF_XDP ZC Tx is used simultaneously with stack
Tx, Tx timeouts occur after going through link flap (admin brings
interface down then up again). HW seem to be unable to transmit
descriptor to the wire after HW tail register bump which in turn causes
bit __QUEUE_STATE_STACK_XOFF to be set forever as
netdev_tx_completed_queue() sees no cleaned bytes on the input.

Fixes: 126cdfe1007a ("ice: xsk: Improve AF_XDP ZC Tx and use batching API")
Fixes: 2d4238f55697 ("ice: Add support for AF_XDP")
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Tested-by: Chandan Kumar Rout <chandanx.rout@intel.com> (A Contingent Worker at Intel)
Signed-off-by: Michal Kubiak <michal.kubiak@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_xsk.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
index a65955eb23c0..72738b8b8a68 100644
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -1048,6 +1048,10 @@  bool ice_xmit_zc(struct ice_tx_ring *xdp_ring)
 
 	ice_clean_xdp_irq_zc(xdp_ring);
 
+	if (!netif_carrier_ok(xdp_ring->vsi->netdev) ||
+	    !netif_running(xdp_ring->vsi->netdev))
+		return true;
+
 	budget = ICE_DESC_UNUSED(xdp_ring);
 	budget = min_t(u16, budget, ICE_RING_QUARTER(xdp_ring));
 
@@ -1091,7 +1095,7 @@  ice_xsk_wakeup(struct net_device *netdev, u32 queue_id,
 	struct ice_vsi *vsi = np->vsi;
 	struct ice_tx_ring *ring;
 
-	if (test_bit(ICE_VSI_DOWN, vsi->state))
+	if (test_bit(ICE_VSI_DOWN, vsi->state) || !netif_carrier_ok(netdev))
 		return -ENETDOWN;
 
 	if (!ice_is_xdp_ena_vsi(vsi))