On Fri, Jun 17, 2022 at 06:58:57PM -0700, John Fastabend wrote:
> Maciej Fijalkowski wrote:
> > Tx side sets EOP and RS bits on descriptors to indicate that a
> > particular descriptor is the last one and needs to generate an irq when
> > it was sent. These bits should not be checked on completion path
> > regardless whether it's the Tx or the Rx. DD bit serves this purpose and
> > it indicates that a particular descriptor is either for Rx or was
> > successfully Txed.
> >
> > Look at DD bit being set in ice_lbtest_receive_frames() instead of EOP
> > and RS pair.
> >
> > Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
>
> Is this a bugfix? If so it should go to bpf tree.
Previous logic worked without this patch by an accident, so I don't change
the behaviour of the loopback self test itself, therefore I was not sure
if this could be classified as a bugfix.
Rx descriptor's status_error0 field has ICE_RX_FLEX_DESC_STATUS0_DD_S and
ICE_RX_FLEX_DESC_STATUS0_EOF_S set, which have the following values:
enum ice_rx_flex_desc_status_error_0_bits {
/* Note: These are predefined bit offsets */
ICE_RX_FLEX_DESC_STATUS0_DD_S = 0,
ICE_RX_FLEX_DESC_STATUS0_EOF_S,
(...)
};
Old code was only ORing two following enums:
enum ice_tx_desc_cmd_bits {
ICE_TX_DESC_CMD_EOP = 0x0001,
ICE_TX_DESC_CMD_RS = 0x0002,
(...)
};
If BIT() was used around ICE_TX_DESC_CMD_EOP and ICE_TX_DESC_CMD_RS and if
they were checked separately then on RS bit we would fail.
(let me also check for EOF bit in next revision)
>
> > ---
> > drivers/net/ethernet/intel/ice/ice_ethtool.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c b/drivers/net/ethernet/intel/ice/ice_ethtool.c
> > index 1e71b70f0e52..b6275a29fa0d 100644
> > --- a/drivers/net/ethernet/intel/ice/ice_ethtool.c
> > +++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c
> > @@ -658,7 +658,7 @@ static int ice_lbtest_receive_frames(struct ice_rx_ring *rx_ring)
> > rx_desc = ICE_RX_DESC(rx_ring, i);
> >
> > if (!(rx_desc->wb.status_error0 &
> > - cpu_to_le16(ICE_TX_DESC_CMD_EOP | ICE_TX_DESC_CMD_RS)))
> > + cpu_to_le16(BIT(ICE_RX_FLEX_DESC_STATUS0_DD_S))))
> > continue;
> >
> > rx_buf = &rx_ring->rx_buf[i];
> > --
> > 2.27.0
> >
>
>
