From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: mpc5121 cache coherency From: Kenneth Johansson To: u-boot-users Content-Type: text/plain Date: Wed, 18 Jun 2008 21:29:51 +0200 Message-Id: <1213817391.27790.27.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, linuxppc-embedded@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , I have tried to speed up u-boot by turning on I/D cache during boot. It sort of works and gives quite a boost but I'm having problems with the ethernet driver that no longer works. What I'm seeing is that the cpu do not notice the ethernet hardwares updates that is located in DRAM. Basically what is expected from a cache incoherent system. Now my question is should not the e300 core detect writes to the DRAM and reload the cached data ?? --- To get cache working I'm turning on the MMU and program some BAT registers to a 1-1 mapping where only DRAM has cache on and all other memory regions like the IMMR, flash ... has cache off.