[U-Boot-Users] Re: Ethernet loopback command

Wolfgang Denk wd at denx.de
Mon Mar 7 20:30:33 CET 2005


in message <D9F0B2AD4531B0449D51C1F09199D484081F14 at mail.kom-saarbruecken.com> you wrote:
> The patch attached provides a command called 'ethloop' which allows to
> perform loopback testing on the current eth device. To achieve this, a

Sorry, but I reject this patch. Test functions like this  one  should
be added as part of the existing POST framework (which probably needs
to  be extended for better architecture support; see the archives for
the previous discussions about this).

> new ethernet packet type (PROT_TEST, 0x0808, AFAIK this is not used
> otherwise) is introduced in net/net.c.
> The patch is against SF CVS from 20050307.

I also don't understand why specific ethernet packet  types  must  be
invented. I don't like such non-standard solutions.

> It is necessary to set the ethernet line into loopback mode either by
> programming the PHY or using a loopback plug. I've tested this on our

So you really should  add  this  as  part  of  the  POST  code  where
appropirate  provisions can be doen. At first glance your patch looks
like it was universal, which it isn't. Actually  I  don;t  see  which
additional  information  you  can  get  from this test that cannot be
gotten from existing network code like ping.

Also, the code is not completely configurable, and was obviously  not
well  tested.  You add some variables even in case the command is not
cnfigured, which wastes memory and causes compiler warnings.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Not one hundred percent efficient, of course ... but nothing ever is.
	-- Kirk, "Metamorphosis", stardate 3219.8

More information about the U-Boot mailing list