From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3C85DE01.6000006@capflow.com> Date: Wed, 06 Mar 2002 10:14:41 +0100 From: Laurent Pinchart MIME-Version: 1.0 To: linuxppc-embedded@lists.linuxppc.org Subject: linux-2.4.18 & copy-back cache mode Content-Type: text/plain; charset=us-ascii; format=flowed Reply-To: laurent.pinchart@capflow.com Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Hi everybody I tried to boot a FADS860T board with the 2.4.18 linux kernel, and experienced problems with cache set in Copy-Back mode. The kernel configuration help states that you can say 'Y' to Copy-Back mode if 'you don't know what that is about', so that's what I did. I then got a 'kernel access of bad area' just after the 'CPM UART driver version 0.03' message. I traced the problem to rs_8xx_init, and found out that a write to .data was causing the crash. After some more investigation I found that disabling Copy-Back mode (thus enabling Write-Through mode) fixed the problem. The problem seems to have been solved in the linuxppc repository, so the purpose if this message is not to ask for help but rather to give help to people who will experience the same problem (no doubt there will be some, as the Copy-Back mode is advised by the kernel configurator). Laurent Pinchart PS: I posted a few patches based on the latest linuxppc tree (to fix some compilation warnings and a problem with xmon) about one week ago. I got no feedback. Have they got through to the list ? ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/