From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 1 Nov 2002 14:57:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 1 Nov 2002 14:57:46 -0500 Received: from user141.3eti.com ([65.220.88.141]:25612 "EHLO mail.aeptec.local") by vger.kernel.org with ESMTP id ; Fri, 1 Nov 2002 14:56:56 -0500 Message-ID: From: "Donepudi, Suneeta" To: "'linux-kernel@vger.kernel.org'" Cc: "Donepudi, Suneeta" Subject: Kernel Panic during memcpy_toio to PCI card Date: Fri, 1 Nov 2002 15:06:59 -0500 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: text/plain; charset="iso-8859-1" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, I would like help in diagnosing a kernel panic while accessing a PCI device. Everything runs fine for sometime and in about 1/2 hour I get a Kernel Panic message saying : "Unable to handle kernel paging request at virtual address 0xc2821000" Analysis with Ksymoops shows that it is happening during a memcpy_toio() with the PCI card. The PCI card uses three Base Address Registers with virtual addresses mapped as follows (after ioremap has been issued): BAR0 = 0xc280f000 BAR1 = 0xc2811000 BAR2 = 0xc2822000 It seems like the kernel panic is complaining about an address which is a combination of BAR1 (lower bytes) and BAR2 (upper bytes). It should really be accessing the BAR1 address at the point the crash occurred. I put the following if-statement just before the memcpy_toio(): ----------------------------------------------------------- if (((long int)pci_bar1) == 0xc2821000) { printk (KERN_ERR "Illegal address for BAR1\n"); return -1; } memcpy_toio (pci_bar1, in_ptr, len); ------------------------------------------------------------ It still caused the crash in the same manner and at the same location. Could someone help me with pointers to where I should start looking ? Disabling interrupts around the memcpy_toio() did not make any difference. Is this a hardware problem with the PCI card ? We are using a Xilinx core with out FPGA build into it. Is there a book I could read to learn more about debugging this in the Kernel ? Thanks a bunch, Suneeta