git: a83f6427c15d - stable/14 - dwc: improve IPv4 transmit checksum offloading

The branch stable/14 has been updated by tuexen:

URL: https://cgit.FreeBSD.org/src/commit/?id=a83f6427c15d0ae24c89c583e72abab9a4669d8f

commit a83f6427c15d0ae24c89c583e72abab9a4669d8f
Author:     Michael Tuexen <tuexen@FreeBSD.org>
AuthorDate: 2026-01-16 11:02:53 +0000
Commit:     Michael Tuexen <tuexen@FreeBSD.org>
CommitDate: 2026-01-21 14:04:21 +0000

    dwc: improve IPv4 transmit checksum offloading
    
    This patch provides two improvements for TCP/IPv4 and UDP/IPv4
    transmit checksum offloading:
    (1) Use *CIC_SEG instead of *CIC_FULL, since FreeBSD always provides
        a pseudo header checksum.
    (2) Don't make transmit IPv4 header checksum offloading a prerequisite
        for TCP/IPv4 or UDP/IPv4 transmit checksum offloading.
    This is the root cause of PR 291696, since right now the epair
    interface does not support transmit IPv4 header checksum offloading,
    but TCP/IPv4 and UDP/IPv4 transmit checksum offloading.
    
    PR:                     291696
    Reviewed by:            Timo Voelker
    Tested by:              Marek Benc
    Differential Revision:  https://reviews.freebsd.org/D54395
    
    (cherry picked from commit f8ddf74175c8013268e65b18750e247306fa088a)
---
 sys/dev/dwc/if_dwc.c | 21 +++++++--------------
 1 file changed, 7 insertions(+), 14 deletions(-)

diff --git a/sys/dev/dwc/if_dwc.c b/sys/dev/dwc/if_dwc.c
index 18e86ac025d4..62de67653761 100644
--- a/sys/dev/dwc/if_dwc.c
+++ b/sys/dev/dwc/if_dwc.c
@@ -685,7 +685,7 @@ dwc_setup_txbuf(struct dwc_softc *sc, int idx, struct mbuf **mp)
 	struct bus_dma_segment segs[TX_MAP_MAX_SEGS];
 	int error, nsegs;
 	struct mbuf * m;
-	uint32_t flags = 0;
+	uint32_t flags;
 	int i;
 	int first, last;
 
@@ -713,19 +713,12 @@ dwc_setup_txbuf(struct dwc_softc *sc, int idx, struct mbuf **mp)
 
 	m = *mp;
 
-	if ((m->m_pkthdr.csum_flags & CSUM_IP) != 0) {
-		if ((m->m_pkthdr.csum_flags & (CSUM_TCP|CSUM_UDP)) != 0) {
-			if (sc->mactype != DWC_GMAC_EXT_DESC)
-				flags = NTDESC1_CIC_FULL;
-			else
-				flags = ETDESC0_CIC_FULL;
-		} else {
-			if (sc->mactype != DWC_GMAC_EXT_DESC)
-				flags = NTDESC1_CIC_HDR;
-			else
-				flags = ETDESC0_CIC_HDR;
-		}
-	}
+	if ((m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) != 0)
+		flags = (sc->mactype != DWC_GMAC_EXT_DESC) ? NTDESC1_CIC_SEG : ETDESC0_CIC_SEG;
+	else if ((m->m_pkthdr.csum_flags & CSUM_IP) != 0)
+		flags = (sc->mactype != DWC_GMAC_EXT_DESC) ? NTDESC1_CIC_HDR : ETDESC0_CIC_HDR;
+	else
+		flags = (sc->mactype != DWC_GMAC_EXT_DESC) ? NTDESC1_CIC_NONE : ETDESC0_CIC_NONE;
 
 	bus_dmamap_sync(sc->txbuf_tag, sc->txbuf_map[idx].map,
 	    BUS_DMASYNC_PREWRITE);