[U-Boot] [PATCH 2/2] net: add driver for Synopsys Ethernet QoS device

[Joe Hershberger]

On Tue, Oct 4, 2016 at 12:13 AM, Stephen Warren <swarren at wwwdotorg.org> wrote:
> On 09/23/2016 03:49 PM, Joe Hershberger wrote:
>>
>> Hi Stephen,
>>
>> Thanks for sending this! I have some comments below.
>>
>> Cheers,
>> -Joe
>>
>> On Mon, Sep 12, 2016 at 12:48 PM, Stephen Warren <swarren at wwwdotorg.org>
>> wrote:
>>>
>>> From: Stephen Warren <swarren at nvidia.com>
>>>
>>> This driver supports the Synopsys Designware Ethernet QoS (Quality of
>>> Service) a/k/a eqos IP block, which is a different design than the HW
>>> supported by the existing designware.c driver. The IP supports many
>>> options for bus type, clocking/reset structure, and feature list. This
>>> driver currently supports the specific configuration used in NVIDIA's
>>> Tegra186 chip, but should be extensible to other combinations quite
>>> easily, as explained in the source.
>
>
>>> diff --git a/drivers/net/dwc_eth_qos.c b/drivers/net/dwc_eth_qos.c
>
>
>> +static int eqos_start(struct udevice *dev)
>
>
>>> +       /* Update the MAC address */
>>> +       val = (plat->enetaddr[5] << 8) |
>>> +               (plat->enetaddr[4]);
>>> +       writel(val, eqos->regs + EQOS_MAC_ADDRESS0_HIGH);
>>> +       val = (plat->enetaddr[3] << 24) |
>>> +               (plat->enetaddr[2] << 16) |
>>> +               (plat->enetaddr[1] << 8) |
>>> +               (plat->enetaddr[0]);
>>> +       writel(val, eqos->regs + EQOS_MAC_ADDRESS0_LOW);
>>
>>
>> This should be implemented in write_hwaddr() op.
>
>
> That op is never called because this driver is only instantiated by device
> tree. Since this code can't be skipped, it can't be moved to that op.

I don't understand what you're saying here. That op is called in
eth_initialize() on every device found in device tree.

>>> +int eqos_send(struct udevice *dev, void *packet, int length)
>
>
>>> +       for (i = 0; i < 1000000; i++) {
>>> +               eqos_inval_desc(tx_desc);
>>> +               if (!(readl(&tx_desc[3]) & EQOS_DESC3_OWN))
>>> +                       return 0;
>>
>>
>> Use wait_bit() here.
>
>
> That function won't work here due to the need to call
> eqos_inval_desc(tx_desc) inside the loop.