RE: [PATCH V3 net-next] net: hns3: Add support to change MTU in HNS3 hardware

[Salil Mehta]

Hi Leon,

 -----Original Message-----
> From: Leon Romanovsky [mailto:leon@xxxxxxxxxx]
> Sent: Monday, August 21, 2017 11:32 AM
> To: Salil Mehta
> Cc: davem@xxxxxxxxxxxxx; Zhuangyuzeng (Yisen); lipeng (Y);
> mehta.salil.lnk@xxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; linux-rdma@xxxxxxxxxxxxxxx; Linuxarm
> Subject: Re: [PATCH V3 net-next] net: hns3: Add support to change MTU
> in HNS3 hardware
> 
> On Mon, Aug 21, 2017 at 11:12:23AM +0100, Salil Mehta wrote:
> > This patch adds the following support to the HNS3 driver:
> > 1. Support to change the Maximum Transmission Unit of a
> >    of a port in the HNS NIC hardware.
Typo-->Will also delete duplicate 'of a'

> > 2. Initializes the supported MTU range for the netdevice.
> >
> > Signed-off-by: lipeng <lipeng321@xxxxxxxxxx>
> > Signed-off-by: Salil Mehta <salil.mehta@xxxxxxxxxx>
> > ---
> > PATCH V3: Addressed some minor comments Leon Romanovsky
> >           1. https://lkml.org/lkml/2017/8/20/27
> > PATCH V2: Addresses comments given by Andrew Lunn
> >           1. https://lkml.org/lkml/2017/8/18/282
> > PATCH V1: Initial Submit
> > ---
> >  .../net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.c | 36
> ++++++++++++++++++++++
> >  .../net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.h |  1 +
> >  2 files changed, 37 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.c
> b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.c
> > index e731f87..c087a9f 100644
> > --- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.c
> > +++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.c
> > @@ -1278,11 +1278,44 @@ static int hns3_ndo_set_vf_vlan(struct
> net_device *netdev, int vf, u16 vlan,
> >  	return ret;
> >  }
> >
> > +static int hns3_nic_change_mtu(struct net_device *netdev, int
> new_mtu)
> > +{
> > +	struct hns3_nic_priv *priv = netdev_priv(netdev);
> > +	struct hnae3_handle *h = priv->ae_handle;
> > +	bool if_running = netif_running(netdev);
> > +	int ret;
> > +
> > +	if (!h->ae_algo->ops->set_mtu)
> > +		return -ENOTSUPP;
> 
> Sorry for not spotting this before, but it should be -EOPNOTSUPP and
> not -ENOTSUPP.
Yes, Maybe I should have seen it earlier as well :(

I Will rectify this.

Thanks 
> 
> > +
> > +	/* if this was called with netdev up then bring netdevice down */
> > +	if (if_running) {
> > +		(void)hns3_nic_net_stop(netdev);
> > +		msleep(100);
> > +	}
> > +
> > +	ret = h->ae_algo->ops->set_mtu(h, new_mtu);
> > +	if (ret) {
> > +		netdev_err(netdev, "failed to change MTU in hardware %d\n",
> > +			   ret);
> > +		return ret;
> > +	}
> > +
> > +	/* if the netdev was running earlier, bring it up again */
> > +	if (if_running) {
> > +		if (hns3_nic_net_open(netdev))
> > +			ret = -EINVAL;
> > +	}
> 
> Anyway, you will resubmit because of wrong error code.
> 	if (if_running && hns3_nic_net_open(netdev))
> 		ret = -EINVAL
> 
> Thanks
> 
> > +
> > +	return ret;
> > +}
> > +
> >  static const struct net_device_ops hns3_nic_netdev_ops = {
> >  	.ndo_open		= hns3_nic_net_open,
> >  	.ndo_stop		= hns3_nic_net_stop,
> >  	.ndo_start_xmit		= hns3_nic_net_xmit,
> >  	.ndo_set_mac_address	= hns3_nic_net_set_mac_address,
> > +	.ndo_change_mtu		= hns3_nic_change_mtu,
> >  	.ndo_set_features	= hns3_nic_set_features,
> >  	.ndo_get_stats64	= hns3_nic_get_stats64,
> >  	.ndo_setup_tc		= hns3_nic_setup_tc,
> > @@ -2752,6 +2785,9 @@ static int hns3_client_init(struct hnae3_handle
> *handle)
> >  		goto out_reg_netdev_fail;
> >  	}
> >
> > +	/* MTU range: (ETH_MIN_MTU(kernel default) - 9706) */
> > +	netdev->max_mtu = HNS3_MAX_MTU - (ETH_HLEN + ETH_FCS_LEN +
> VLAN_HLEN);
> > +
> >  	return ret;
> >
> >  out_reg_netdev_fail:
> > diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.h
> b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.h
> > index a6e8f15..7e87461 100644
> > --- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.h
> > +++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.h
> > @@ -76,6 +76,7 @@ enum hns3_nic_state {
> >  #define HNS3_RING_NAME_LEN			16
> >  #define HNS3_BUFFER_SIZE_2048			2048
> >  #define HNS3_RING_MAX_PENDING			32768
> > +#define HNS3_MAX_MTU				9728
> >
> >  #define HNS3_BD_SIZE_512_TYPE			0
> >  #define HNS3_BD_SIZE_1024_TYPE			1
> > --
> > 2.7.4
> >
> >
> > --
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