[U-Boot] [PATCH] net: asix: don't pad odd-length TX packets

Marek Vasut marex at denx.de
Fri Feb 28 11:54:39 CET 2014


On Thursday, February 27, 2014 at 09:38:48 PM, Simon Glass wrote:
> Hi Stephen,
> 
> On 27 February 2014 13:27, Stephen Warren <swarren at wwwdotorg.org> wrote:
> > From: Stephen Warren <swarren at nvidia.com>
> > 
> > For Ethernet/USB RX packets, the ASIX HW pads odd-sized packets so that
> > they have an even size. Currently, asix_recv() does remove this padding,
> > and asic_send() adds equivalent padding in the TX path. However, the HW
> > does not appear to need this packing for TX packets in practical testing
> > with "ASIX Elec. Corp. AX88x72A 000001" Vendor: 0x0b95 Product 0x7720
> > Version 0.1. The Linux kernel does no such padding for the TX path.
> > 
> > Remove the padding from the TX path:
> > 
> > * For consistency with the Linux kernel.
> > * NVIDIA has a Tegra simulator which validates that the length of USB
> > 
> >   packets sent to an ASIX device matches the packet length value inside
> >   the packet data. Having U-Boot and the kernel do the same thing when
> >   creating the TX packets simplifies the simulator's validation.
> > 
> > Cc: Lucas Stach <dev at lynxeye.de>
> > Cc: Marek Vasut <marex at denx.de>
> > Cc: Simon Glass <sjg at chromium.org>
> > Signed-off-by: Stephen Warren <swarren at nvidia.com>
> 
> My notes indicate I added this due to a problem I had at the time with
> bootp. However, since you have tested it, perhaps the root cause was
> somewhere else.
> 
> Acked-by: Simon Glass <sjg at chromium.org>

Tested on two different ASIX dongles:

0x2001:0x3c05 ; DUB-E100 ; D-Link Corporation
0x0b95:0x7720 ; ZoWii ; Zoltan Tech

Acked-by: Marek Vasut <marex at denx.de>
Tested-by: Marek Vasut <marex at denx.de>

Best regards,
Marek Vasut


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