Re: [RFC/PATCH 18/18] ravb: Add set_feature support for RZ/G2L

From: Sergey Shtylyov <s.shtylyov@omp.ru>
To: Biju Das <biju.das.jz@bp.renesas.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>
Cc: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Sergei Shtylyov <sergei.shtylyov@gmail.com>,
	"Geert Uytterhoeven" <geert+renesas@glider.be>,
	Adam Ford <aford173@gmail.com>,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	<netdev@vger.kernel.org>, <linux-renesas-soc@vger.kernel.org>,
	Chris Paterson <Chris.Paterson2@renesas.com>,
	Biju Das <biju.das@bp.renesas.com>
Subject: Re: [RFC/PATCH 18/18] ravb: Add set_feature support for RZ/G2L
Date: Thu, 30 Sep 2021 23:39:26 +0300	[thread overview]
Message-ID: <b19b7b83-7b0b-2c48-afc2-6fbf36a5ad98@omp.ru> (raw)
In-Reply-To: <20210923140813.13541-19-biju.das.jz@bp.renesas.com>

On 9/23/21 5:08 PM, Biju Das wrote:

> This patch adds set_feature support for RZ/G2L.
> 
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> ---
>  drivers/net/ethernet/renesas/ravb.h      | 32 ++++++++++++++
>  drivers/net/ethernet/renesas/ravb_main.c | 56 +++++++++++++++++++++++-
>  2 files changed, 87 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
> index d42e8ea981df..2275f27c0672 100644
> --- a/drivers/net/ethernet/renesas/ravb.h
> +++ b/drivers/net/ethernet/renesas/ravb.h
> @@ -209,6 +209,8 @@ enum ravb_reg {
>  	CXR56	= 0x0770,	/* Documented for RZ/G2L only */
>  	MAFCR	= 0x0778,
>  	CSR0     = 0x0800,	/* Documented for RZ/G2L only */
> +	CSR1     = 0x0804,	/* Documented for RZ/G2L only */
> +	CSR2     = 0x0808,	/* Documented for RZ/G2L only */

   These are the TOE regs (CSR0 included), they only exist on RZ/G2L, no?

[...]
> @@ -978,6 +980,36 @@ enum CSR0_BIT {
>  	CSR0_RPE	= 0x00000020,
>  };
>  

   *enum* CSR0_BIT should be here (as we concluded).

> +enum CSR1_BIT {
[...]
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index 72aea5875bc5..641ae5553b64 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
[...]
> @@ -2290,7 +2308,38 @@ static void ravb_set_rx_csum(struct net_device *ndev, bool enable)
>  static int ravb_set_features_rgeth(struct net_device *ndev,
>  				   netdev_features_t features)
>  {
> -	/* Place holder */
> +	netdev_features_t changed = features ^ ndev->features;
> +	unsigned int reg;

   u32 reg;

> +	int error;
> +
> +	reg = ravb_read(ndev, CSR0);

   ... as this function returns u32.

> +
> +	ravb_write(ndev, reg & ~(CSR0_RPE | CSR0_TPE), CSR0);
> +	error = ravb_wait(ndev, CSR0, CSR0_RPE | CSR0_TPE, 0);
> +	if (error) {
> +		ravb_write(ndev, reg, 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, I don't understand this... it would be nice if someone knowledgeable about the offloads
would look at this... Although, without the register documentation it's possibly vain...

> +		} else {
> +			ravb_write(ndev, 0, CSR1);
> +		}
> +	}
> +	ravb_write(ndev, reg, CSR0);
> +
> +	ndev->features = features;
> +
>  	return 0;
>  }
>  
> @@ -2432,6 +2481,11 @@ static const struct ravb_hw_info rgeth_hw_info = {
>  	.set_feature = ravb_set_features_rgeth,
>  	.dmac_init = ravb_dmac_init_rgeth,
>  	.emac_init = ravb_emac_init_rgeth,
> +	.net_hw_features = (NETIF_F_HW_CSUM | NETIF_F_RXCSUM),
> +	.gstrings_stats = ravb_gstrings_stats_rgeth,
> +	.gstrings_size = sizeof(ravb_gstrings_stats_rgeth),
> +	.stats_len = ARRAY_SIZE(ravb_gstrings_stats_rgeth),

    These seem unrelated, couldn't it be moved to a spearate patch?

> +	.max_rx_len = RGETH_RX_BUFF_MAX + RAVB_ALIGN - 1,

   This seems unrelsated and misplaced too.

[...]

MBR, Sergey