[PATCH net-next v2 1/1] net: stmmac: check CBS input values before configuration

[PATCH net-next v2 1/1] net: stmmac: check CBS input values before configuration

[Gan Yi Fang]

From: Michael Sit Wei Hong <michael.wei.hong.sit@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 including zero.
Sendslope is always a negative value including zero.
Hicredit is always a positive value including zero.
Locredit is always a negative value including zero.

Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit@intel.com>
Signed-off-by: Gan, Yi Fang <yi.fang.gan@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);
-- 
2.34.1

Re: [PATCH net-next v2 1/1] net: stmmac: check CBS input values before configuration

[Andrew Lunn]

On Wed, Nov 01, 2023 at 02:19:20PM +0800, Gan Yi Fang wrote:
> From: Michael Sit Wei Hong <michael.wei.hong.sit@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 including zero.
> Sendslope is always a negative value including zero.
> Hicredit is always a positive value including zero.
> Locredit is always a negative value including zero.

Which of these conditional are specific to stmmac, and which are
generic to CBS? Anything which is generic to CBS i would expect to be
checked at a higher level, rather than in every driver implementing
CBS.

	Andrew

RE: [PATCH net-next v2 1/1] net: stmmac: check CBS input values before configuration

[Gan, Yi Fang]

Hi Andrew,

The values are not specific to stmmac driver.
It is more making sense to implement the checking at higher level.
Let's close the review for this patch.


Best Regards,
Fang

> -----Original Message-----
> From: Andrew Lunn <andrew@lunn.ch>
> Sent: Wednesday, November 1, 2023 8:36 PM
> To: Gan, Yi Fang <yi.fang.gan@intel.com>
> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>; Jose Abreu
> <joabreu@synopsys.com>; David S . Miller <davem@davemloft.net>; Eric
> Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo
> Abeni <pabeni@redhat.com>; Maxime Coquelin
> <mcoquelin.stm32@gmail.com>; netdev@vger.kernel.org; linux-stm32@st-md-
> mailman.stormreply.com; linux-arm-kernel@lists.infradead.org; linux-
> kernel@vger.kernel.org; Looi, Hong Aun <hong.aun.looi@intel.com>; Voon,
> Weifeng <weifeng.voon@intel.com>; Song, Yoong Siang
> <yoong.siang.song@intel.com>; Sit, Michael Wei Hong
> <michael.wei.hong.sit@intel.com>
> Subject: Re: [PATCH net-next v2 1/1] net: stmmac: check CBS input values
> before configuration
> 
> On Wed, Nov 01, 2023 at 02:19:20PM +0800, Gan Yi Fang wrote:
> > From: Michael Sit Wei Hong <michael.wei.hong.sit@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 including zero.
> > Sendslope is always a negative value including zero.
> > Hicredit is always a positive value including zero.
> > Locredit is always a negative value including zero.
> 
> Which of these conditional are specific to stmmac, and which are generic to
> CBS? Anything which is generic to CBS i would expect to be checked at a higher
> level, rather than in every driver implementing CBS.
> 
> 	Andrew