The branch main has been updated by adrian:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=73cd4048807dc0b3a5329bfc9a80ea4bf2d975fd

commit 73cd4048807dc0b3a5329bfc9a80ea4bf2d975fd
Author:     Nick Price <[email protected]>
AuthorDate: 2026-07-19 16:40:46 +0000
Commit:     Adrian Chadd <[email protected]>
CommitDate: 2026-07-19 16:40:46 +0000

    aq(4): drop errored RX frames instead of resetting the interface
    
    aq_isc_rxd_pkt_get() returned EBADMSG when a receive descriptor's
    MAC/receive-error bit (rx_stat bit 0) was set.  iflib treats any error
    from isc_rxd_pkt_get() as a fatal ring fault and answers with
    IFC_DO_RESET -- a full interface reinitialization.  A per-frame receive
    error is not a ring fault: on a marginal link or cable the Atlantic
    delivers errored frames continuously, so each one triggered another
    reset and the interface reset-stormed itself into carrying no traffic
    instead of merely dropping the bad frames.
    
    The Atlantic delivers errored frames to the host by design (Linux drops
    them in software via buff->is_error), and iflib offers no per-frame
    error return that isn't a reset.  Follow the vmxnet3 model: on a receive
    error zero the fragment lengths and return success.  iflib then discards
    the packet (assemble_segments() excludes zero-length fragments) while
    still recycling the descriptors through the refill path -- no reset.
    Also drop frames flagged with an RX-DMA fault (rdm_err), not just the
    MAC-error bit; and keep iri_len non-zero on that drop path, since iflib
    asserts iri_len != 0.
    
    The genuinely structural errors -- more segments than isc_rx_nsegments,
    or a pkt_len inconsistent with the descriptor count -- still return
    EBADMSG, since those indicate a confused ring where a reset is the right
    recovery.
    
    Reviewed by:    adrian
    Differential Revision:  https://reviews.freebsd.org/D58136
---
 sys/dev/aq/aq_ring.c | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/sys/dev/aq/aq_ring.c b/sys/dev/aq/aq_ring.c
index 8307fb0b3474..6afec86c63bc 100644
--- a/sys/dev/aq/aq_ring.c
+++ b/sys/dev/aq/aq_ring.c
@@ -333,11 +333,13 @@ aq_isc_rxd_pkt_get(void *arg, if_rxd_info_t ri)
        if_t ifp;
        int cidx, rc = 0, i;
        size_t len, total_len;
+       bool is_error = false;
 
        AQ_DBG_ENTERA("[%d] start=%d", ring->index, ri->iri_cidx);
        cidx = ri->iri_cidx;
        ifp = iflib_get_ifp(aq_dev->ctx);
        i = 0;
+       total_len = 0;
 
        do {
                if (i >= aq_dev->sctx->isc_rx_nsegments)
@@ -348,11 +350,15 @@ aq_isc_rxd_pkt_get(void *arg, if_rxd_info_t ri)
                trace_aq_rx_descr(ring->index, cidx,
                    (volatile uint64_t *)rx_desc);
 
-               if ((rx_desc->wb.rx_stat & BIT(0)) != 0)
-                       goto rx_err;
+               /* MAC error (rx_stat) or RX-DMA fault (rdm_err) -> drop. */
+               if ((rx_desc->wb.rx_stat & BIT(0)) != 0 || rx_desc->wb.rdm_err)
+                       is_error = true;
 
                if (!rx_desc->wb.eop) {
                        len = ring->rx_buf_size;
+               } else if (is_error) {
+                       total_len = le32toh(rx_desc->wb.pkt_len);
+                       len = 0;
                } else {
                        total_len = le32toh(rx_desc->wb.pkt_len);
                        if (total_len < (size_t)i * ring->rx_buf_size)
@@ -375,6 +381,19 @@ aq_isc_rxd_pkt_get(void *arg, if_rxd_info_t ri)
                cidx = aq_next(cidx, ring->rx_size - 1);
        } while (!rx_desc->wb.eop);
 
+       ri->iri_nfrags = i;
+       ri->iri_len = total_len;
+
+       /* Per-frame RX error: drop (zero-length frags), don't reset. */
+       if (is_error) {
+               counter_u64_add(ring->stats.rx_err, 1);
+               for (i = 0; i < ri->iri_nfrags; i++)
+                       ri->iri_frags[i].irf_len = 0;
+               if (ri->iri_len == 0)
+                       ri->iri_len = 1;        /* iflib asserts iri_len != 0 */
+               goto exit;
+       }
+
        if ((if_getcapenable(ifp) & IFCAP_RXCSUM) != 0) {
                aq_rx_set_cso_flags(rx_desc, ri);
        }
@@ -383,9 +402,6 @@ aq_isc_rxd_pkt_get(void *arg, if_rxd_info_t ri)
                ri->iri_flowid = le32toh(rx_desc->wb.rss_hash);
        }
 
-       ri->iri_len = total_len;
-       ri->iri_nfrags = i;
-
        counter_u64_add(ring->stats.rx_bytes, total_len);
        counter_u64_add(ring->stats.rx_pkts, 1);
        goto exit;

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