[Enable Designware XGMAC VLAN Stripping Feature 2/2] net: stmmac: dwxgmac2: Add support for HW-accelerated VLAN Stripping

[Ng, Boon Khai]

> -----Original Message-----
> From: Krzysztof Kozlowski <krzk at kernel.org>
> Sent: Friday, July 21, 2023 6:11 PM
> To: Boon at ecsmtp.png.intel.com; Khai at ecsmtp.png.intel.com; "Ng
> <boon.khai.ng"@intel.com; Giuseppe Cavallaro <peppe.cavallaro at st.com>;
> Alexandre Torgue <alexandre.torgue at foss.st.com>; Jose Abreu
> <joabreu at synopsys.com>; David S . Miller <davem at davemloft.net>; Eric
> Dumazet <edumazet at google.com>; Jakub Kicinski <kuba at kernel.org>;
> Paolo Abeni <pabeni at redhat.com>; Maxime Coquelin
> <mcoquelin.stm32 at gmail.com>; netdev at vger.kernel.org; linux-stm32 at st-
> md-mailman.stormreply.com; linux-arm-kernel at lists.infradead.org; linux-
> kernel at vger.kernel.org
> Cc: Ng, Boon Khai <boon.khai.ng at intel.com>; Shevchenko, Andriy
> <andriy.shevchenko at intel.com>; Tham, Mun Yew
> <mun.yew.tham at intel.com>; Swee, Leong Ching
> <leong.ching.swee at intel.com>; G Thomas, Rohan
> <rohan.g.thomas at intel.com>; Shevchenko Andriy
> <andriy.shevchenko at linux.intel.com>
> Subject: Re: [Enable Designware XGMAC VLAN Stripping Feature 2/2] net:
> stmmac: dwxgmac2: Add support for HW-accelerated VLAN Stripping
> 
> On 21/07/2023 08:26, Boon at ecsmtp.png.intel.com wrote:
> > From: Boon Khai Ng <boon.khai.ng at intel.com>
> >
> > Currently, VLAN tag stripping is done by software driver in
> > stmmac_rx_vlan(). This patch is to Add support for VLAN tag stripping
> > by the MAC hardware and MAC drivers to support it.
> > This is done by adding rx_hw_vlan() and set_hw_vlan_mode() callbacks
> > at stmmac_ops struct which are called from upper software layer.
> ...
> 
> >  	if (priv->dma_cap.vlhash) {
> >  		ndev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
> >  		ndev->features |= NETIF_F_HW_VLAN_STAG_FILTER; diff --
> git
> > a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > index 23d53ea04b24..bd7f3326a44c 100644
> > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > @@ -543,6 +543,12 @@ stmmac_probe_config_dt(struct platform_device
> *pdev, u8 *mac)
> >  			plat->flags |= STMMAC_FLAG_TSO_EN;
> >  	}
> >
> > +	/* Rx VLAN HW Stripping */
> > +	if (of_property_read_bool(np, "snps,rx-vlan-offload")) {
> > +		dev_info(&pdev->dev, "RX VLAN HW Stripping\n");
> 
> Why? Drop.
> 

This is an dts option export to dts for user to choose whether or not they 
Want a Hardware stripping or a software stripping. 

May I know what is the reason to drop this?

> 
> 
> Best regards,
> Krzysztof