From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.semihalf.com (mail.semihalf.com [83.12.36.68]) by ozlabs.org (Postfix) with ESMTP id 5648FDE05E for ; Sat, 2 Jun 2007 09:30:29 +1000 (EST) Received: from localhost (unknown [127.0.0.1]) by mail.semihalf.com (Postfix) with ESMTP id 17C081432C for ; Sat, 2 Jun 2007 01:04:54 +0200 (CEST) Received: from mail.semihalf.com ([127.0.0.1]) by localhost (mail.semihalf.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 11191-07 for ; Sat, 2 Jun 2007 01:04:52 +0200 (CEST) Message-ID: <4660A611.9020909@semihalf.com> Date: Sat, 02 Jun 2007 01:04:49 +0200 From: Marian Balakowicz MIME-Version: 1.0 To: linuxppc-dev@ozlabs.org Subject: BestComm ATA task on MPC52xx Content-Type: text/plain; charset=ISO-8859-2 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, I am working on bringing up a DMA support for ATA controller on MPC52xx and I am facing problems for which I am not pretty sure what the actual root cause is. There was a John Rigby's patch last year, which was based on arch/ppc and drivers/ide (mpc52xx_ide.c). I use arch/powerpc and adopted to libata version of mpc52xx_ide.c which is now merged to vanilla and is called pata_mpc52xx.c. On top of this I have John Rigby's modifications converted from ide to libata. Problems appear with the first DMA transfer attempt, which happens during a driver probe when partition table is read. There shall be a interrupt signaling a transfer end and the handler (not present in John Rigby's code) should do the transfer closing. But the interrupt is not received and after the cmd timeouts it looks like ATA controller registers, BestComm registers, buffer descriptors and BestComm ATA task variables are unchanged. So, it seems that for some reason ATA BestComm task did not run/do it's job. Did anyone had any success with ATA DMA on 52xx? Or maybe hear about newer version of the ATA BestComm task, or some useful ways of debugging BestComm stuff? I am planning to post my working code but need a day or two to clean it up a little. Thanks, Marian