Re: [PATCH net-next 08/18] ravb: Add R-Car common features

From: Sergei Shtylyov <sergei.shtylyov@gmail.com>
To: Biju Das <biju.das.jz@bp.renesas.com>,
	"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, 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: [PATCH net-next 08/18] ravb: Add R-Car common features
Date: Tue, 27 Jul 2021 23:48:51 +0300	[thread overview]
Message-ID: <d493b1d2-6d05-9eb3-c5f5-f3828938fe56@gmail.com> (raw)
In-Reply-To: <20210722141351.13668-9-biju.das.jz@bp.renesas.com>

Hello!

On 7/22/21 5:13 PM, Biju Das wrote:

> The below features are supported by both R-Car Gen2 and Gen3.
> 
> 1) magic packet detection
> 2) multiple TSRQ support
> 3) extended descriptor in rx

   I think this one should better be called timestamping...

> 4) No half duplex support

   Couldn't we avoid the "negative" features?

> 5) override mtu change

   Hm, I'd vote for the individual patches covering only single feature...

> Add features bits to support the same.
> 
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
>  drivers/net/ethernet/renesas/ravb_main.c | 110 +++++++++++++++--------
>  1 file changed, 71 insertions(+), 39 deletions(-)
> 
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index b3c99f974632..4ef2565534d2 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
[...]
> @@ -680,11 +694,14 @@ static void ravb_rcv_snd_enable(struct net_device *ndev)
>  /* function for waiting dma process finished */
>  static int ravb_stop_dma(struct net_device *ndev)
>  {
> +	struct ravb_private *priv = netdev_priv(ndev);
> +	const struct ravb_drv_data *info = priv->info;
>  	int error;
>  
>  	/* Wait for stopping the hardware TX process */
> -	error = ravb_wait(ndev, TCCR,
> -			  TCCR_TSRQ0 | TCCR_TSRQ1 | TCCR_TSRQ2 | TCCR_TSRQ3, 0);
> +	if (info->features & RAVB_MULTI_TSRQ)
> +		error = ravb_wait(ndev, TCCR,
> +				  TCCR_TSRQ0 | TCCR_TSRQ1 | TCCR_TSRQ2 | TCCR_TSRQ3, 0);
>  	if (error)

   What if the above *if* skips the ravb_wait() call -- didn't you get a complaint from gcc
about the unnintialized variable?

[...]
> @@ -808,11 +826,14 @@ static bool ravb_queue_interrupt(struct net_device *ndev, int q)
>  
>  static bool ravb_timestamp_interrupt(struct net_device *ndev)
>  {
> +	struct ravb_private *priv = netdev_priv(ndev);
> +	const struct ravb_drv_data *info = priv->info;
>  	u32 tis = ravb_read(ndev, TIS);
>  
>  	if (tis & TIS_TFUF) {
>  		ravb_write(ndev, ~(TIS_TFUF | TIS_RESERVED), TIS);
> -		ravb_get_tx_tstamp(ndev);
> +		if (info->features & RAVB_EX_RX_DESC)

   Yeah, definitely a bad feature name...

> +			ravb_get_tx_tstamp(ndev);
>  		return true;
>  	}
>  	return false;
[...]
> @@ -1069,15 +1091,17 @@ static int ravb_phy_init(struct net_device *ndev)
>  		netdev_info(ndev, "limited PHY to 100Mbit/s\n");
>  	}
>  
> -	/* 10BASE, Pause and Asym Pause is not supported */
> -	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_10baseT_Half_BIT);
> -	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_10baseT_Full_BIT);
> -	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_Pause_BIT);
> -	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_Asym_Pause_BIT);
> +	if (info->features & RAVB_NO_HALF_DUPLEX) {
> +		/* 10BASE, Pause and Asym Pause is not supported */
> +		phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_10baseT_Half_BIT);
> +		phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_10baseT_Full_BIT);
> +		phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_Pause_BIT);
> +		phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_Asym_Pause_BIT);
>  
> -	/* Half Duplex is not supported */
> -	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_1000baseT_Half_BIT);
> -	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_100baseT_Half_BIT);
> +		/* Half Duplex is not supported */
> +		phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_1000baseT_Half_BIT);
> +		phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_100baseT_Half_BIT);

    Mhm? Some of the half-duplex modes sre unsupported still?

[...]
> @@ -1314,8 +1338,9 @@ static void ravb_get_wol(struct net_device *ndev, struct ethtool_wolinfo *wol)
>  static int ravb_set_wol(struct net_device *ndev, struct ethtool_wolinfo *wol)
>  {
>  	struct ravb_private *priv = netdev_priv(ndev);
> +	const struct ravb_drv_data *info = priv->info;
>  
> -	if (wol->wolopts & ~WAKE_MAGIC)
> +	if ((wol->wolopts & ~WAKE_MAGIC) || (!(info->features & RAVB_MAGIC)))

   Parens about !x not needed. And I think the second operand should come first instead...

>  		return -EOPNOTSUPP;
>  
>  	priv->wol_enabled = !!(wol->wolopts & WAKE_MAGIC);
[...]
> @@ -1595,28 +1621,30 @@ static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev)
>  	desc->dptr = cpu_to_le32(dma_addr);
>  
>  	/* TX timestamp required */
> -	if (q == RAVB_NC) {
> -		ts_skb = kmalloc(sizeof(*ts_skb), GFP_ATOMIC);
> -		if (!ts_skb) {
> -			if (num_tx_desc > 1) {
> -				desc--;
> -				dma_unmap_single(ndev->dev.parent, dma_addr,
> -						 len, DMA_TO_DEVICE);
> +	if (info->features & RAVB_EX_RX_DESC) {

   Definitely a bad name...

[...]
> @@ -2205,8 +2235,10 @@ static int ravb_probe(struct platform_device *pdev)
>  	}
>  	clk_prepare_enable(priv->refclk);
>  
> -	ndev->max_mtu = 2048 - (ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN);
> -	ndev->min_mtu = ETH_MIN_MTU;
> +	if (info->features & RAVB_OVERRIDE_MTU_CHANGE) {

   Why? :-/ Could you tell me more details?

> +		ndev->max_mtu = 2048 - (ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN);
> +		ndev->min_mtu = ETH_MIN_MTU;
> +	}
>  
>  	priv->num_tx_desc = info->num_tx_desc;
>  

MBR, Sergei