From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Roese Date: Tue, 18 Dec 2007 10:03:41 +0100 Subject: [U-Boot-Users] MPC5121 (and MPC5200) ethernet initialization delay In-Reply-To: <20071218081644.BE34C248AC@gemini.denx.de> References: <20071218081644.BE34C248AC@gemini.denx.de> Message-ID: <200712181003.42358.sr@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Tuesday 18 December 2007, Wolfgang Denk wrote: > > autonegotiation only when the ethernet interface is used. Upon TFTP > > download or something like this. So there should be no delay at all in > > U-Boot related to this ethernet initialization when you don't use > > ethernet. > > Right, that's how it should be in an ideal world. > > However, things are not that simple. > > First, the perception that this is how things should work has not been > there forever. It has riped over time, and older boards / ports do > things differently. > > Second, there are some CPUs / boards where "initializing" the ether- > net just requires to whack a PY reset or simply take the PHT out of > reset etc. Autonegotiation then takes place while U-Boot is doing > other things, and by the time you want to use the Ethernet for a TFTP > download or so it will be available with no or at least with greatly > reduced delay. Right. I know of such ports too and don't see any problems here since no delay is imposed. > But there are other implementations which wait for > autonegotiation to complete. I don't see a reason why a board should wait for autonegotionation to complete, when the interface is not used. This should be fixed. Best regards, Stefan ===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office at denx.de =====================================================================