From owner-freebsd-hardware Thu Jul 18 20:04:32 1996 Return-Path: owner-hardware Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id UAA18341 for hardware-outgoing; Thu, 18 Jul 1996 20:04:32 -0700 (PDT) Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.2.228.19]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id UAA18332 for ; Thu, 18 Jul 1996 20:04:28 -0700 (PDT) Received: (from bde@localhost) by godzilla.zeta.org.au (8.6.12/8.6.9) id MAA30281; Fri, 19 Jul 1996 12:47:51 +1000 Date: Fri, 19 Jul 1996 12:47:51 +1000 From: Bruce Evans Message-Id: <199607190247.MAA30281@godzilla.zeta.org.au> To: E00114@vnet.atea.be, alex@fa.tdktca.com Subject: Re: Multiple COM ports with same IRQ Cc: freebsd-hardware@freebsd.org Sender: owner-hardware@freebsd.org X-Loop: FreeBSD.org Precedence: bulk >> ISA boxes can >> have hardware installed (accidentally?) with devices sharing the same IRQ, but >> the drivers cannot deal with it. >The sharing of interrupts between ISA devices is an electrical >constraint. When two devices are attempting to use a common IRQ line, That's why he only wanted to share them for EISA/ISA boxes :-). sio should be able to handle it if the hardware permits level triggered interrupts. It doesn't depend on the trigger level and doesn't have board-specific multiport optimizations (only board-specific initializations for AST boards), so it shouldn't be able to tell the difference between a a bunch of ports connected to the same level triggered IRQ and a nondescript non-AST multiport board. Bruce