From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pantelis Antoniou Date: Wed, 14 Apr 2004 09:00:48 +0300 Subject: [U-Boot-Users] SCC Ethernet and "Linux crashes by early packets" ??? In-Reply-To: <20040408213000.B30A4C133F@atlas.denx.de> References: <20040408213000.B30A4C133F@atlas.denx.de> Message-ID: <407CD390.9010003@intracom.gr> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Wolfgang Denk wrote: >In message <40757661.50905@imc-berlin.de> you wrote: > >>the CHANGELOG contains the lines >> >>* Make sure SCC Ethernet is always stopped by the time we boot Linux >> to avoid Linux crashes by early packets coming in. >> >>in "Changes for U-Boot 1.0.2". >> >>My two question: >> >>1.) How can I find out which changes in the CVS do excactly this? >> > >Checking the CVS logs? > >Try: cvs diff -r1.3 -r1.4 post/ether.c > > >>2.) Do we need the same with 8xx FEC Ethernet? >> > >I don't think so. Note that the ethernet interface was left in a non- >stopped state by the POST code. Normal network use will (should) >correctly shut down the interface. > > > Actually we most certainly do. I was bitten by the same bug the past week and have a patch ready; I'm just waiting for my other patches to be included in order to sent it. When we leave any ethernet on with DMA capability, there is a small window of time before the new code reprograms the controller and stops the DMA. In the mean time if a packet is received (typically a broadcast) it will write over in the physical memory where u-boot had placed it's buffers. It's a crapshoot. Most of the times no-one will notice since the possibility of actually overwritting something important is very small. >Best regards, > >Wolfgang Denk > > Regards Pantelis