A Debian user reported that a simple program that repeatedly opens and closes a serial device will eventually cause an irq line to be disabled. References: http://bugzilla.kernel.org/show_bug.cgi?id=7750 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=404815
Proposed upstream patch: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=8528b0f1de1101c6002036fd53638fb21111d0ea
Created attachment 312322 [details] Upstream patch for this issue
Created attachment 312323 [details] Proposed backported patch
Created attachment 312324 [details] Reproducer Source: http://bugzilla.kernel.org/attachment.cgi?id=9958&action=view
The bug is reported to be reproducible if the kernel is compiled with CONFIG_PREEMPT_NONE=y. I have tested this on rhel-4, and rhel-5, but without success. On rhel-5, the kernel is compiled with CONFIG_PREEMPT_VOLUNTARY=y, and /dev/ttyS* are not accessible to local unprivileged users (unless you are in uucp group for /dev/ttyS[1-3]). Let's get it fixed anyway.
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
in kernel-2.6.18-100.el5 You can download this test kernel from http://people.redhat.com/dzickus/el5
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2009-0225.html