Date: Wed, 21 Apr 1999 20:23:29 +0100 (BST) From: Doug Rabson <dfr@nlsystems.com> To: Peter Wemm <peter@netplex.com.au> Cc: Jason Thorpe <thorpej@nas.nasa.gov>, William Woods <wwoods@cybcon.com>, "Jordan K. Hubbard" <jkh@zippy.cdrom.com>, "Alain G. Fabry" <fabry@coserve.org>, freebsd-alpha@freebsd.org Subject: Re: External modems on Alpha..... Message-ID: <Pine.BSF.4.05.9904212019570.85882-100000@herring.nlsystems.com> In-Reply-To: <19990421152417.11EB11F2A@spinner.netplex.com.au>
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On Wed, 21 Apr 1999, Peter Wemm wrote: > Jason Thorpe wrote: > > On Wed, 21 Apr 1999 00:02:01 -0700 > > "William Woods" <wwoods@cybcon.com> wrote: > > > > > OK.....I am getting a crap load oF "silo overflows" when connected to the > > > net. I am useing a external Hayes Acura 33/56k fax-modem. I am guessing th > is > > > is a serial port problem, but am not sure. I have this modem attached to > > > /dev/cuaa0 (com1). > > > > I doubt it's a serial port problem. It's more likely a problem of the FreeBS > D > > kernel not reasonably coping witht he fact that all device interrupts come > > in at the same interrupt level on the Alpha (so network and disk controller > > interrupts block serial port reception). > > I saw this yesterday and couldn't believe my eyes.. I wonder if it's > possible to use a soft or lazy masking system like on the i386.. Can > interrupts be individually masked if needed? Interrupts can be masked (there are generally different masks for isa and pci and the pci mask is platform independant). I haven't experimented with it much, so I'm not sure what the right approach to a lazy interrupt masking scheme would be. We have plenty of pointless code between the palcode signalling the interrupt and actual delivery to the driver so there is lots of scope for improvement before changing the algorithm. -- Doug Rabson Mail: dfr@nlsystems.com Nonlinear Systems Ltd. Phone: +44 181 442 9037 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message
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