RE: [PATCH net-next 1/3] r8152: separate USB_RX_EARLY_AGG

From: Hayes Wang
Date: Thu Feb 12 2015 - 01:04:18 EST


Sergei Shtylyov; netdev@xxxxxxxxxxxxxxx
[...]
> > > + ocp_data = tp->coalesce / 8;
> >
> > Why not do it in the initializer?
>
> This is for patch #3. The patch #3 would use this function.
> The unit of the relative setting from the ethtool is 1 us.
> However, the unit for the hw is 8 us. Therefore, I save the
> value with the unit of 1 us, and transfer it to the unit of
> the hw when setting.

I think I misunderstand what you mean. I think you mean I
have to combine

u32 ocp_data;
ocp_data = tp->coalesce / 8;

into

u32 ocp_data = tp->coalesce / 8;

I would correct it.

> > > + ocp_write_word(tp, MCU_TYPE_USB, USB_RX_EARLY_TIMEOUT, ocp_data);
> > > +}
> > > +
> > > +static void r8153_set_rx_early_size(struct r8152 *tp)
> > > +{
> > > + struct net_device *dev = tp->netdev;
> >
> > Not sure you actually need this variable.
>
> If I replace dev->mtu with tp->netdev->mtu, the line would
> more than 80 characters. This is used to avoid it. Should
> I remove it?
>
> > > + u32 ocp_data;
> > > +
> > > + ocp_data = (agg_buf_sz - dev->mtu - VLAN_ETH_HLEN - VLAN_HLEN) / 4;
> >
> > Why not in initializer?
>
> This is for patch #2. The patch #2 would use this function.
> It has to be re-calculated when the mtu is changed, or the
> function is called when the linking status changes to ON.

I think you mean I have to combine

u32 ocp_data;
ocp_data = (agg_buf_sz - dev->mtu - VLAN_ETH_HLEN - VLAN_HLEN) / 4;

into

u32 ocp_data = (agg_buf_sz - dev->mtu - VLAN_ETH_HLEN - VLAN_HLEN) / 4;

I would correct it.

> > > + ocp_write_word(tp, MCU_TYPE_USB, USB_RX_EARLY_SIZE, ocp_data);
> > > }
> > [...]
> > > @@ -3911,6 +3907,13 @@ static int rtl8152_probe(struct
> > usb_interface *intf,
> > > tp->mii.reg_num_mask = 0x1f;
> > > tp->mii.phy_id = R8152_PHY_ID;
> > >
> > > + if (udev->speed == USB_SPEED_SUPER)
> > > + tp->coalesce = COALESCE_SUPER;
> > > + else if (udev->speed == USB_SPEED_HIGH)
> > > + tp->coalesce = COALESCE_HIGH;
> > > + else
> > > + tp->coalesce = COALESCE_SLOW;
> >
> > This is asking to be a *switch* statement.
>
> Excuse me. I don't understand what you mean.
> The usb speed is determined when the device is plugged on
> the usb host controller or usb hub. The usb speed wouldn't
> chage unless you unplug the device and plug it to another
> port with different usb speed. Therefore, I provide different
> default values for different usb speed.

I think you mean

switch (udev->speed) {
case USB_SPEED_SUPER:
...

I would correct it.

Best Regards,
Hayes
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