Date: Thu, 30 May 2013 19:30:41 GMT From: "Majdi S. Abbas" <msa@latt.net> To: freebsd-gnats-submit@FreeBSD.org Subject: i386/179115: Writing to uart1 causes host to hang Message-ID: <201305301930.r4UJUfak092030@oldred.FreeBSD.org> Resent-Message-ID: <201305301940.r4UJe0YX039388@freefall.freebsd.org>
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>Number: 179115 >Category: i386 >Synopsis: Writing to uart1 causes host to hang >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-i386 >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Thu May 30 19:40:00 UTC 2013 >Closed-Date: >Last-Modified: >Originator: Majdi S. Abbas >Release: 9.1-RELEASE >Organization: Lattice, L.L.C. >Environment: root@procyon:/dev # uname -a FreeBSD procyon.latt.net 9.1-RELEASE FreeBSD 9.1-RELEASE #2: Wed May 29 16:01:42 UTC 2013 msa@procyon.latt.net:/usr/src/sys/i386/compile/NET4801 i386 root@procyon:/dev # dmesg | grep uart uart0: <16550 or compatible> at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0 uart0: console (9600,n,8,1) uart1: <16550 or compatible> at port 0x2f8-0x2ff irq 3 on isa0 uart0: <16550 or compatible> at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0 uart0: console (9600,n,8,1) uart1: <16550 or compatible> at port 0x2f8-0x2ff irq 3 on isa0 >Description: Opening /dev/cuau1 works successfully; incoming data arrives and is read just fine. stty verifies parameters normally, and this is a standard serial port on real hardware (no USB or anything else involved here.) Any attempt to write to /dev/cuau1 while open causes the system to hang; it returns ping and completes 3 way handshakes but is unresponsive via ssh and on console. Same cabling, same configuration works on another OS. Levels have been verified with a digital volt meter, and RS232 analyzer. >How-To-Repeat: 100% repeatable with either my build or GENERIC from boottime. >Fix: >Release-Note: >Audit-Trail: >Unformatted:
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