From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261352AbTIXNYn (ORCPT ); Wed, 24 Sep 2003 09:24:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261353AbTIXNYn (ORCPT ); Wed, 24 Sep 2003 09:24:43 -0400 Received: from moutng.kundenserver.de ([212.227.126.171]:40690 "EHLO moutng.kundenserver.de") by vger.kernel.org with ESMTP id S261352AbTIXNYl (ORCPT ); Wed, 24 Sep 2003 09:24:41 -0400 X-KENId: 00001511KEN019B37E1 X-KENRelayed: 00001511KEN019B37E1@PCDR800 Date: Wed, 24 Sep 2003 15:18:13 +0200 From: "Christoph Baumann" Subject: mysterious prblem with IO memory To: Reply-To: "Christoph Baumann" Message-Id: <004b01c3829e$4fe29980$2265a8c0@dirtyentw> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" X-Priority: 3 Organization: SORCUS Computer GmbH Content-Transfer-Encoding: 7bit X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, developing a driver (currently with a vanilla 2.4.20 kernel) for a PCI card i encountered a mysterious behaviour. I get the IO addresses from the card configuration space and use ioremap_nocache to get virtual addresses for usage with write[bwl]. This works to some extend (the card behaves as expected). But then at some random moment i get error messages about dereferencing a NULL pointer and severe crashes afterwards. When i put a printk("%p\n",address) before each write[bwl] everything is fine (appart from lots of log entries). I also tried wmb() after the write commands which didn't help. Any idea? Mit freundlichen Gruessen / Best regards Dipl.-Phys. Christoph Baumann --- SORCUS Computer GmbH Im Breitspiel 11 c D-69126 Heidelberg Tel.: +49(0)6221/3206-0 Fax: +49(0)6221/3206-66