Date: Fri, 22 Jan 1999 00:51:49 +0100 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: Mike Smith <mike@smith.net.au> Cc: Bill Trost <trost@cloud.rain.com>, mobile@FreeBSD.ORG Subject: Re: Reclaiming irqs for unsupported PCI hardware? Message-ID: <802.916962709@critter.freebsd.dk> In-Reply-To: Your message of "Thu, 21 Jan 1999 11:28:18 PST." <199901211928.LAA10433@dingo.cdrom.com>
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In message <199901211928.LAA10433@dingo.cdrom.com>, Mike Smith writes: >Once the card is gone, all of the >registers in the mapped space read all-1s. This should not be relied on. It is my understanding that you will get fireworks bus-cycles on CardBus in this situation, and it will be left to the BIOS writer to figure out what should happen since I belive we end up in SMM mode in that case... Also I have not seen any documentation saying the all-1s is a standard, but would accept a survey of pcic's which show this to be universal so far. > - Polling for the card's presence every iteration of the interrupt > handler loop. This is absurdly expensive. Don't suggest polling > once on interrupt entry, unless you can guarantee the card won't be > pulled during the interrupt handler's execution. There is no way to guarantee that the card will not be pulled in the next N microseconds. -- Poul-Henning Kamp FreeBSD coreteam member phk@FreeBSD.ORG "Real hackers run -current on their laptop." FreeBSD -- It will take a long time before progress goes too far! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-mobile" in the body of the message
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