From mboxrd@z Thu Jan 1 00:00:00 1970 From: whitnl73@juno.com Subject: Re: Serial/Parallel conflicts Date: Fri, 31 Jan 2003 21:46:52 -0500 (EST) Sender: linux-serial-owner@vger.kernel.org Message-ID: <20030201.071711.8.0.whitnl73@juno.com> References: <20030131055640.GA763@wheat.boylan.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <20030131055640.GA763@wheat.boylan.org> List-Id: linux-serial@vger.kernel.org To: RossBoylan@stanfordalumni.org Cc: rich+ml@lclogic.com, linux-serial@vger.kernel.org On Thu, 30 Jan 2003, Ross Boylan wrote: > This is kind of a "please tell me it isn't so message." > My efforts to dislodge ttyS2 (aka COM3, my internal modem) from IRQ 5 > have been unsuccessful. The BIOS offers no direct control over it, > since it is not a built in serial port. > > In particular, neither of the following worked, even with reboots: > 1. reprogramming the card via /proc/isapnp. If I set the IRQ to a > value other than shown in the dmesg start up, I can't communicate with > the modem at all. This doesn't make any sense to me, since the serial > port is actually part of the card (as I understand it), and presumably > is reprogrammed by isapnp. Only if it is an ISA Plug 'N' Pray card. I have several internal modems, one has jumpers to set the port and IRQ, the other has switches. I guess the IRQ for a PCI card would be set by the BIOS, but I don;t have any hardware that new. > > Is the problem that the serial driver can not adjust to changes in > port locations after start up? Not so. The values the serial driver _uses_ (tries to use) can be set using /bin/setserial at any time. This has no effect on what the hardware uses, but it is useful particularly to set the IRQ to some non-default value so FI com1 and com3 amd/or com2 and com4 don't conflict. By default they do. You have to set the hardware some other way first - jumpers, isapnptools or the BIOS. > > 2. I set the BIOS manually to use IRQ 5 for the parallel port. I > thought this would force it to put ttyS2 elsewhere, but it doesn't > seem to. The good news is that both the modem and the parallel port > appear to work sharing the same interrupt, so I may have symptomatic > relief. > > 3. I also disabled COM1 in BIOS, hoping to get the system to use the > newly availabe interrupt. It put one of the ethernet cards there > (IRQ4). > > Anyway, please tell me this info isn't just buried in the ESCD with no > way to kick it out short of flashing the whole thing! Isn't there > some other way to influence it? Is the full story "ECSD sets > location; serial driver reads it; nothing changes it"? Serial driver doesn't read it (unless instructed by system administrator (setserial auto_irq autoconfig)). See man setserial. Lawson -- ---oops--- ________________________________________________________________ Sign Up for Juno Platinum Internet Access Today Only $9.95 per month! Visit www.juno.com