sc->hw.min_frame_size is only used for TBI mode, which is only available on the 82543 according to em_set_media_type()
You'd need to carefully analyze how the TBI_ACCEPT macro is used to see what's right here. The macro even seems to assume that the vlan tag size might be part of min_frame_size. Michele Curti [michele.cu...@gmail.com] wrote: > Hi, > in sys/dev/pci/if_em.c at line 469 there is: > sc->hw.min_frame_size = > ETHER_MIN_LEN + ETHER_CRC_LEN; > > But ETHER_MIN_LEN already includes the CRC size: > #define ETHER_MIN_LEN 64 /* Minimum frame length, CRC included */ > > In revision 1.41 the code changed in this way: > sc->hw.min_frame_size = > - MINIMUM_ETHERNET_PACKET_SIZE + ETHER_CRC_LEN; > + ETHER_MIN_LEN + ETHER_CRC_LEN; > > But MINIMUM_ETHERNET_PACKET_SIZE was the size without CRC. > > #define MINIMUM_ETHERNET_FRAME_SIZE 64 /* With FCS */ > #define ETHERNET_FCS_SIZE 4 > #define MINIMUM_ETHERNET_PACKET_SIZE \ > (MINIMUM_ETHERNET_FRAME_SIZE - ETHERNET_FCS_SIZE) > > So I attached the following diff to restore the original minimum > size (by the way, what's the effect of having min_frame_size set > to 68? Discarding valid packets sized from 64 to 67?) > > Regards, > Michele > > > Index: sys/dev/pci/if_em.c > =================================================================== > RCS file: /cvs/src/sys/dev/pci/if_em.c,v > retrieving revision 1.336 > diff -u -p -r1.336 if_em.c > --- sys/dev/pci/if_em.c 25 Jul 2017 20:45:18 -0000 1.336 > +++ sys/dev/pci/if_em.c 2 Feb 2018 11:13:43 -0000 > @@ -466,8 +466,7 @@ em_attach(struct device *parent, struct > MAX_JUMBO_FRAME_SIZE; > } > > - sc->hw.min_frame_size = > - ETHER_MIN_LEN + ETHER_CRC_LEN; > + sc->hw.min_frame_size = ETHER_MIN_LEN; > > /* Allocate Transmit Descriptor ring */ > if (em_dma_malloc(sc, sc->sc_tx_slots * sizeof(struct em_tx_desc),
