diff mbox series

[net,2/5] igc: Fix TX drops in XDP ZC

Message ID 20250402173900.1957261-3-anthony.l.nguyen@intel.com (mailing list archive)
State Accepted
Commit d931cf9b38da0f533cacfe51c863a9912e67822f
Delegated to: Netdev Maintainers
Headers show
Series Intel Wired LAN Driver Updates 2025-04-02 (igc, e1000e, ixgbe, idpf) | 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: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 10 of 10 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
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: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 29 this patch: 29
netdev/source_inline success Was 0 now: 0
netdev/contest fail net-next-2025-04-02--21-00 (tests: 953)

Commit Message

Tony Nguyen April 2, 2025, 5:38 p.m. UTC 
From: Zdenek Bouska <zdenek.bouska@siemens.com>

Fixes TX frame drops in AF_XDP zero copy mode when budget < 4.
xsk_tx_peek_desc() consumed TX frame and it was ignored because of
low budget. Not even AF_XDP completion was done for dropped frames.

It can be reproduced on i226 by sending 100000x 60 B frames with
launch time set to minimal IPG (672 ns between starts of frames)
on 1Gbit/s. Always 1026 frames are not sent and are missing a
completion.

Fixes: 9acf59a752d4c ("igc: Enable TX via AF_XDP zero-copy")
Signed-off-by: Zdenek Bouska <zdenek.bouska@siemens.com>
Reviewed-by: Song Yoong Siang <yoong.siang.song@intel.com>
Reviewed-by: Florian Bezdeka <florian.bezdeka@siemens.com>
Tested-by: Mor Bar-Gabay <morx.bar.gabay@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 27c99ff59ed4..156d123c0e21 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -3042,7 +3042,7 @@  static void igc_xdp_xmit_zc(struct igc_ring *ring)
 	 * descriptors. Therefore, to be safe, we always ensure we have at least
 	 * 4 descriptors available.
 	 */
-	while (xsk_tx_peek_desc(pool, &xdp_desc) && budget >= 4) {
+	while (budget >= 4 && xsk_tx_peek_desc(pool, &xdp_desc)) {
 		struct igc_metadata_request meta_req;
 		struct xsk_tx_metadata *meta = NULL;
 		struct igc_tx_buffer *bi;