RE: [RFC 03/12] ravb: Fillup ravb_set_features_gbeth() stub

From: Biju Das <biju.das.jz@bp.renesas.com>
To: Sergey Shtylyov <s.shtylyov@omp.ru>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>,
	Sergey Shtylyov <s.shtylyov@omprussia.ru>,
	Adam Ford <aford173@gmail.com>, Andrew Lunn <andrew@lunn.ch>,
	Yuusuke Ashizuka <ashiduka@fujitsu.com>,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"linux-renesas-soc@vger.kernel.org" 
	<linux-renesas-soc@vger.kernel.org>,
	Chris Paterson <Chris.Paterson2@renesas.com>,
	Biju Das <biju.das@bp.renesas.com>,
	Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>
Subject: RE: [RFC 03/12] ravb: Fillup ravb_set_features_gbeth() stub
Date: Wed, 6 Oct 2021 07:43:55 +0000	[thread overview]
Message-ID: <OS0PR01MB59223E020F4AEE30CD13F9E786B09@OS0PR01MB5922.jpnprd01.prod.outlook.com> (raw)
In-Reply-To: <17eb621c-05f8-155b-24ed-5445f445c6ce@omp.ru>

Hi Sergei,

Thanks for the feedback.

> Subject: Re: [RFC 03/12] ravb: Fillup ravb_set_features_gbeth() stub
> 
> On 10/5/21 2:06 PM, Biju Das wrote:
> 
> > Fillup ravb_set_features_gbeth() function to support RZ/G2L.
> > Also set the net_hw_features bits supported by GbEthernet
> >
> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> [...]
> 
> > diff --git a/drivers/net/ethernet/renesas/ravb_main.c
> > b/drivers/net/ethernet/renesas/ravb_main.c
> > index ed0328a90200..37f50c041114 100644
> > --- a/drivers/net/ethernet/renesas/ravb_main.c
> > +++ b/drivers/net/ethernet/renesas/ravb_main.c
> [...]
> > @@ -2086,7 +2087,37 @@ static void ravb_set_rx_csum(struct net_device
> > *ndev, bool enable)  static int ravb_set_features_gbeth(struct
> net_device *ndev,
> >  				   netdev_features_t features)
> >  {
> > -	/* Place holder */
> > +	netdev_features_t changed = features ^ ndev->features;
> > +	int error;
> > +	u32 csr0;
> > +
> > +	csr0 = ravb_read(ndev, CSR0);
> > +	ravb_write(ndev, csr0 & ~(CSR0_RPE | CSR0_TPE), CSR0);
> > +	error = ravb_wait(ndev, CSR0, CSR0_RPE | CSR0_TPE, 0);
> > +	if (error) {
> > +		ravb_write(ndev, csr0, CSR0);
> > +		return error;
> > +	}
> > +
> > +	if (changed & NETIF_F_RXCSUM) {
> > +		if (features & NETIF_F_RXCSUM)
> > +			ravb_write(ndev, CSR2_ALL, CSR2);
> > +		else
> > +			ravb_write(ndev, 0, CSR2);
> > +	}
> > +
> > +	if (changed & NETIF_F_HW_CSUM) {
> > +		if (features & NETIF_F_HW_CSUM) {
> > +			ravb_write(ndev, CSR1_ALL, CSR1);
> > +			ndev->features |= NETIF_F_CSUM_MASK;
> 
>    Hm, the >linux/netdev_features.h> says those are contradictory to have
> both NETIF_F_HW_CSUM and NETIF_F_CSUM_MASK set...

It is a mistake from my side, I am taking out this setting. Any way below code overrides it.
This will answer all your comments below.

Regards,
Biju

> 
> > +		} else {
> > +			ravb_write(ndev, 0, CSR1);
> 
>    No need to mask off the 'features' field?
> 
> > +		}
> > +	}
> > +	ravb_write(ndev, csr0, CSR0);
> > +
> > +	ndev->features = features;
> 
>    Mhm, doesn't that clear NETIF_F_CSUM_MASK?
> 
> [...]
> 
> MBR, Sergey