Subject: Re: [PATCH 4/5] net: ethernet: bgmac: add NS2 support

From: Jon Mason <jon.mason-dY08KVG/lbpWk0Htik3J/[email-masked]>
Date: Thu, 27 Oct 2016 16:51:21 -0400

On Wed, Oct 26, 2016 at 02:50:39PM -0700, Florian Fainelli wrote:
> On 10/26/2016 12:36 PM, Jon Mason wrote:
> > Add support for the variant of amac hardware present in the Broadcom
> > Northstar2 based SoCs.  Northstar2 requires an additional register to be
> > configured with the port speed/duplexity (NICPM).  This can be added to
> > the link callback to hide it from the instances that do not use this.
> > Also, the bgmac_chip_reset() was intentionally removed to prevent the
> > resetting of the chip to the default values on open.  Finally, clearing
> > of the pending interrupts on init is required due to observed issues on
> > some platforms.
> > 
> > Signed-off-by: Jon Mason <jon.mason-dY08KVG/lbpWk0Htik3J/[email-masked]>
> > ---
> 
> > +static void bgmac_nicpm_speed_set(struct net_device *net_dev)
> > +{
> > +	struct bgmac *bgmac = netdev_priv(net_dev);
> > +	u32 val;
> > +
> > +	if (!bgmac->plat.nicpm_base)
> > +		return;
> > +
> > +	val = NICPM_IOMUX_CTRL_INIT_VAL;
> > +	switch (bgmac->net_dev->phydev->speed) {
> > +	default:
> > +		pr_err("Unsupported speed.  Defaulting to 1000Mb\n");
> > +	case SPEED_1000:
> > +		val |= NICPM_IOMUX_CTRL_SPD_1000M << NICPM_IOMUX_CTRL_SPD_SHIFT;
> > +		break;
> > +	case SPEED_100:
> > +		val |= NICPM_IOMUX_CTRL_SPD_100M << NICPM_IOMUX_CTRL_SPD_SHIFT;
> > +		break;
> > +	case SPEED_10:
> > +		val |= NICPM_IOMUX_CTRL_SPD_10M << NICPM_IOMUX_CTRL_SPD_SHIFT;
> > +		break;
> > +	}
> > +
> > +	writel(val, bgmac->plat.nicpm_base + NICPM_IOMUX_CTRL);
> > +
> > +	usleep_range(10, 100);
> 
> Does not seem like a good idea, do you need that sleep?

Oops, that's not supposed to be there.  Removed.

> > +
> > +	bgmac_adjust_link(bgmac->net_dev);
> > +}
> > +
> >  static int platform_phy_connect(struct bgmac *bgmac)
> >  {
> >  	struct phy_device *phy_dev;
> >  
> > -	phy_dev = of_phy_get_and_connect(bgmac->net_dev, bgmac->dev->of_node,
> > -					 bgmac_adjust_link);
> > +	if (bgmac->plat.nicpm_base)
> > +		phy_dev = of_phy_get_and_connect(bgmac->net_dev,
> > +						 bgmac->dev->of_node,
> > +						 bgmac_nicpm_speed_set);
> > +	else
> > +		phy_dev = of_phy_get_and_connect(bgmac->net_dev,
> > +						 bgmac->dev->of_node,
> > +						 bgmac_adjust_link);
> >  	if (!phy_dev) {
> >  		dev_err(bgmac->dev, "Phy connect failed\n");
> >  		return -ENODEV;
> >  	}
> >  
> > +	if (bgmac->feature_flags & BGMAC_FEAT_LANE_SWAP)
> > +		phy_dev->dev_flags |= PHY_BRCM_EXP_LANE_SWAP;
> > +
> >  	return 0;
> >  }
> >  
> > @@ -140,6 +188,9 @@ static int bgmac_probe(struct platform_device *pdev)
> >  
> >  	platform_set_drvdata(pdev, bgmac);
> >  
> > +	if (of_property_read_bool(np, "brcm,enet-phy-lane-swap"))
> > +		bgmac->feature_flags |= BGMAC_FEAT_LANE_SWAP;
> > +
> >  	/* Set the features of the 4707 family */
> >  	bgmac->feature_flags |= BGMAC_FEAT_CLKCTLST;
> >  	bgmac->feature_flags |= BGMAC_FEAT_NO_RESET;
> > @@ -182,6 +233,14 @@ static int bgmac_probe(struct platform_device *pdev)
> >  	if (IS_ERR(bgmac->plat.idm_base))
> >  		return PTR_ERR(bgmac->plat.idm_base);
> >  
> > +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nicpm_base");
> > +	if (regs) {
> > +		bgmac->plat.nicpm_base = devm_ioremap_resource(&pdev->dev,
> > +							       regs);
> > +		if (IS_ERR(bgmac->plat.nicpm_base))
> > +			return PTR_ERR(bgmac->plat.nicpm_base);
> > +	}
> > +
> >  	bgmac->read = platform_bgmac_read;
> >  	bgmac->write = platform_bgmac_write;
> >  	bgmac->idm_read = platform_bgmac_idm_read;
> > @@ -213,6 +272,7 @@ static int bgmac_remove(struct platform_device *pdev)
> >  static const struct of_device_id bgmac_of_enet_match[] = {
> >  	{.compatible = "brcm,amac",},
> >  	{.compatible = "brcm,nsp-amac",},
> > +	{.compatible = "brcm,ns2-amac",},
> >  	{},
> >  };
> >  
> > diff --git a/drivers/net/ethernet/broadcom/bgmac.c b/drivers/net/ethernet/broadcom/bgmac.c
> > index 38876ec..1796208 100644
> > --- a/drivers/net/ethernet/broadcom/bgmac.c
> > +++ b/drivers/net/ethernet/broadcom/bgmac.c
> > @@ -1082,6 +1082,9 @@ static void bgmac_enable(struct bgmac *bgmac)
> >  /* http://bcm-v4.sipsolutions.net/mac-gbit/gmac/chipinit */
> >  static void bgmac_chip_init(struct bgmac *bgmac)
> >  {
> > +	/* Clear any erroneously pending interrupts */
> > +	bgmac_write(bgmac, BGMAC_INT_STATUS, ~0);
> > +
> >  	/* 1 interrupt per received frame */
> >  	bgmac_write(bgmac, BGMAC_INT_RECV_LAZY, 1 << BGMAC_IRL_FC_SHIFT);
> >  
> > @@ -1158,8 +1161,6 @@ static int bgmac_open(struct net_device *net_dev)
> >  	struct bgmac *bgmac = netdev_priv(net_dev);
> >  	int err = 0;
> >  
> > -	bgmac_chip_reset(bgmac);
> > -
> 
> Is this removal intentional? Maybe it should be special cased with
> checking for a NS2 BGMAC instance and not do it in that case?

The reset seems completely unnecessary.  There is already 2 resets in
the probe routine, another reset serves no purpose.  I can add it
back, as it does not seem to have the negative effect I was seeing
before.

Of course, if I remove this one I should remove the reset in the close
too (which seems even more unnecessary, but I didn't remove it).

Thanks,
Jon

> -- 
> Florian
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