From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: skge: reboot on sysfs resource0 access Date: Fri, 9 Sep 2005 11:01:53 -0700 Message-ID: <20050909110153.5a2e2e90@localhost.localdomain> References: <200509091938.18079.bernd.schubert@pci.uni-heidelberg.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: bernd.schubert@pci.uni-heidelberg.de, netdev@oss.sgi.com Return-path: To: bernd-schubert@gmx.de In-Reply-To: <200509091938.18079.bernd.schubert@pci.uni-heidelberg.de> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Fri, 9 Sep 2005 19:38:17 +0200 Bernd Schubert wrote: > Hello, > > today we tried 2.6.13 on our server and also tried to use the skge driver. > Well, in principle it works fine, until I became curious about the sysfs > values. Stupid me, I was using the midnight commander to read the values. > When I opened "/sys/bus/pci/drivers/skge/0000:01:01.0/resource0", the system > immediately rebooted. After the reboot we tested using cat to the resource0 > file, which gave an input/output error. Using again the mc, the system again > immediately rebooted. > Well, I guess I better don't use the midnight commander in the future, but > somehow I think it shouldn't cause the system to reboot, should it? Is the > i/o error of cat supposed to happen? > Don't do that! resource0 is the pci space for the card and reading it directly accesses the memory mapped space. The register is sparse, and some places are unaccessable. Accessing non-existent memory will cause system to hang and if you are lucky a timeout and reboot. Sorry, this is not a driver bug.