[U-Boot] [PATCH v3 1/4] Add support for SMSC95XX USB 2.0 10/100MBit Ethernet Adapter

[Rabin Vincent]

On Thu, Apr 14, 2011 at 04:03, Simon Glass <sjg at chromium.org> wrote:
> On Wed, Apr 13, 2011 at 12:16 PM, Andy Fleming <afleming at gmail.com> wrote:
>>> +       read_buf &= ~HW_CFG_RXDOFF_;
>>> +
>>> +#ifdef CONFIG_TEGRA2
>>> +       /* Tegra2 requires NET_IP_ALIGN = 0 */
>>> +#define NET_IP_ALIGN 0
>>> +#else
>>> +       /* set Rx data offset=2, Make IP header aligns on word boundary. */
>>> +#define NET_IP_ALIGN 2
>>> +#endif
>>> +       read_buf |= NET_IP_ALIGN << 9;
>>
>>
>> This is usually a performance optimization, which isn't all that
>> useful in u-boot. And doesn't it mean that you can't rx directly into
>> the NetRxPackets array?
>
> Actually I think it doesn't work without it. In any case I will remove
> it for now.

In the latest version of this patch, you still keep the RX data offset
as 2.  I don't see how this can work, because if you do this you would
have to handle the offset in the smsc95xx_recv() function, but you're
not doing that.

It's probably simplest to just keep the RX data offset as zero.  I had
to do that to get this driver to work on the PandaBoard (OMAP4) too.