Date: Fri, 21 May 1999 10:07:24 +0200 From: Ladavac Marino <mladavac@metropolitan.at> To: 'Mike Smith' <mike@smith.net.au>, Joel Ray Holveck <joelh@gnu.org> Cc: Doug Rabson <dfr@nlsystems.com>, Peter Wemm <peter@netplex.com.au>, Tommy Hallgren <thallgren@yahoo.com>, freebsd-hackers@FreeBSD.ORG Subject: RE: Lazy SPLs Message-ID: <55586E7391ACD211B9730000C1100276179612@r-lmh-wi-100.corpnet.at>
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> -----Original Message----- > From: Mike Smith [SMTP:mike@smith.net.au] > Sent: Friday, May 21, 1999 2:16 AM > To: Joel Ray Holveck > Cc: Doug Rabson; Peter Wemm; Tommy Hallgren; > freebsd-hackers@FreeBSD.ORG > Subject: Re: Lazy SPLs > > > > > Why mask out the interrupts at all, instead of queuing them in > handler > > level? > > Level-triggered interrupts are persistent conditions, not queueable > events. They typically require device-driver level intervention to be > > cleared. This is a major error in the PCI design (no surprises > there). > [ML] Whoa there! That's the MAJOR advantage of PCI design. Open collector, active low, level triggered interrupts are the only possibility for interupt line sharing without programmatically accessible registers on card which say "yes, I am still interrupting". Active high, edge triggered interrupts are an abomination (there is no way to reliably share the interrupt line and you cannot even wire or it). They are the reason why one never has enough interrupt lines on ISA. > -- > \\ The mind's the standard \\ Mike Smith > \\ of the man. \\ msmith@freebsd.org > \\ -- Joseph Merrick \\ msmith@cdrom.com > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-hackers" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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