On Fri, Dec 18, 2020 at 12:30:20PM -0800, Florian Fainelli wrote:
> On 12/18/20 12:24 PM, Vladimir Oltean wrote:
> > Hi Florian,
> >
> > On Fri, Dec 18, 2020 at 09:38:43AM -0800, Florian Fainelli wrote:
> >> The driver is already allocating receive buffers of 2KiB and the
> >> Ethernet MAC is configured to accept frames up to UMAC_MAX_MTU_SIZE.
> >>
> >> Fixes: bfcb813203e6 ("net: dsa: configure the MTU for switch ports")
> >> Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
> >> ---
> >> drivers/net/ethernet/broadcom/bcmsysport.c | 1 +
> >> 1 file changed, 1 insertion(+)
> >>
> >> diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c
> >> b/drivers/net/ethernet/broadcom/bcmsysport.c
> >> index 0fdd19d99d99..b1ae9eb8f247 100644
> >> --- a/drivers/net/ethernet/broadcom/bcmsysport.c
> >> +++ b/drivers/net/ethernet/broadcom/bcmsysport.c
> >> @@ -2577,6 +2577,7 @@ static int bcm_sysport_probe(struct platform_device
> >> *pdev)
> >> NETIF_F_HW_VLAN_CTAG_TX;
> >> dev->hw_features |= dev->features;
> >> dev->vlan_features |= dev->features;
> >> + dev->max_mtu = UMAC_MAX_MTU_SIZE;
> >>
> >> /* Request the WOL interrupt and advertise suspend if available */
> >> priv->wol_irq_disabled = 1;
> >> --
> >> 2.25.1
> >>
> >
> > Do you want to treat the SYSTEMPORT Lite differently?
> >
> > /* Set maximum frame length */
> > if (!priv->is_lite)
> > umac_writel(priv, UMAC_MAX_MTU_SIZE, UMAC_MAX_FRAME_LEN);
> > else
> > gib_set_pad_extension(priv);
>
> SYSTEMPORT Lite does not actually validate the frame length, so setting
> a maximum number to the buffer size we allocate could work, but I don't
> see a reason to differentiate the two types of MACs here.
And if the Lite doesn't validate the frame length, then shouldn't it
report a max_mtu equal to the max_mtu of the attached DSA switch, plus
the Broadcom tag length? Doesn't the b53 driver support jumbo frames?
