[PATCH net-next 1/1] net: stmmac: check CBS input values before configuration

[Gan, Yi Fang]

Hi,

Value zero is allowed. I will update V2 with the commit msg updated.

Best regards,
Gan Yi Fang

> -----Original Message-----
> From: Drewek, Wojciech <wojciech.drewek at intel.com>
> Sent: Friday, October 27, 2023 6:08 PM
> To: Gan, Yi Fang <yi.fang.gan at intel.com>; Alexandre Torgue
> <alexandre.torgue at foss.st.com>; Jose Abreu <joabreu at synopsys.com>;
> David S . Miller <davem at davemloft.net>; Eric Dumazet
> <edumazet at google.com>; Jakub Kicinski <kuba at kernel.org>; Paolo Abeni
> <pabeni at redhat.com>; Maxime Coquelin <mcoquelin.stm32 at gmail.com>;
> netdev at vger.kernel.org; linux-stm32 at st-md-mailman.stormreply.com; linux-
> arm-kernel at lists.infradead.org; linux-kernel at vger.kernel.org
> Cc: Looi, Hong Aun <hong.aun.looi at intel.com>; Voon, Weifeng
> <weifeng.voon at intel.com>; Song, Yoong Siang
> <yoong.siang.song at intel.com>; Sit, Michael Wei Hong
> <michael.wei.hong.sit at intel.com>
> Subject: Re: [PATCH net-next 1/1] net: stmmac: check CBS input values before
> configuration
> 
> 
> 
> On 27.10.2023 08:11, Gan Yi Fang wrote:
> > From: Michael Sit Wei Hong <michael.wei.hong.sit at intel.com>
> >
> > Add check for below conditions before proceeding to configuration.
> > A message will be prompted if the input value is invalid.
> >
> > Idleslope minus sendslope should equal speed_div.
> > Idleslope is always a positive value.
> > Sendslope is always a negative value.
> > Hicredit is always a positive value.
> > Locredit is always a negative value.
> 
> Can those values be equal to 0? The code allows it but the commit msg
> doesn't mention that.
> Some drivers does not allow 0, lan966x_cbs_add e.g. Would be good to
> double check that.
> 
> >
> > Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit at intel.com>
> > Signed-off-by: Gan, Yi Fang <yi.fang.gan at intel.com>
> > ---
> >  drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
> b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
> > index ac41ef4cbd2f..e8a079946f84 100644
> > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
> > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
> > @@ -381,6 +381,11 @@ static int tc_setup_cbs(struct stmmac_priv *priv,
> >  		return -EOPNOTSUPP;
> >  	}
> >
> > +	if ((qopt->idleslope - qopt->sendslope != speed_div) ||
> > +	    qopt->idleslope < 0 || qopt->sendslope > 0 ||
> > +	    qopt->hicredit < 0 || qopt->locredit > 0)
> > +		return -EINVAL;
> > +
> >  	mode_to_use = priv->plat->tx_queues_cfg[queue].mode_to_use;
> >  	if (mode_to_use == MTL_QUEUE_DCB && qopt->enable) {
> >  		ret = stmmac_dma_qmode(priv, priv->ioaddr, queue,
> MTL_QUEUE_AVB);