Patch-ID# 104108-01 Keywords: Cray Virtual Console cvc cvcredir boot panic CS6400 cray4d Synopsis: SunOS 5.4 CS6400: cvc panic during boot Date: Nov/19/96 Solaris Release: 2.4_CS6400 SunOS release: 5.4_CS6400 Unbundled Product: Unbundled Release: Topic: SunOS 5.4 CS6400: cvc panic during boot NOTE: NOTE 1: This patch replaces the Cray patch C641019-02. You do not need to install this patch if you have already installed C641019-02. NOTE 2: BugID's with six digits or less are related to Cray SPR's. BugId's fixed with this patch: 86421 88162 Changes incorporated in this version: Relevant Architectures: sparc Patches accumulated and obsoleted by this patch: 641019-02 Patches which conflict with this patch: Patches required with this patch: Obsoleted by: Files included with this patch: /kernel/drv/cvc /kernel/drv/cvcredir Problem Description: (from C641019-02) 88162: CVC PANIC ON BOOTUP FOLLOWING MESSAGE "WARNING: CVC_REDIR: CVCINPUT_Q NULL!" System can panic during startup flow under certain timing conditions. The specific cause is the cvcd daemon opens its CVC devices _before_ the kernel has set up its console descriptor. This is not a bug in itself, but it causes the panic in the cvc driver because the driver doesn't properly handle this scenario. (from C641019-01) 86421: CVC PANICS ON HIGH OUTPUT BOOT SEQUENCE When booting with alot of console output, the kernel may panic in cvc driver (cvc_wput). A race condition can occur between the time the cvcoutput_q is initialized and the streams queue is actually enabled. This fix combines the two operation to guarantee nobody attempts to use cvcoutput_q before it is completely ready. We recreated the problem by booting with debug versions of the "ip" and "arp" drivers and setting moddebug to 0x80000000 (booted w/kadb). Patch Installation Instructions: -------------------------------- Refer to the Install.info file within the patch for instructions on using the generic 'installpatch' and 'backoutpatch' scripts provided with each patch. Any other special or non-generic installation instructions should be described below. Special Install Instructions: ----------------------------- none