Date: Mon, 25 Oct 1999 12:22:31 -0600 From: Warner Losh <imp@village.org> To: nate@mt.sri.com (Nate Williams) Cc: arch@freebsd.org Subject: Re: Racing interrupts Message-ID: <199910251822.MAA41899@harmony.village.org> In-Reply-To: Your message of "Mon, 25 Oct 1999 10:46:53 MDT." <199910251646.KAA13773@mt.sri.com> References: <199910251646.KAA13773@mt.sri.com> <199910240608.AAA34462@harmony.village.org>
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In message <199910251646.KAA13773@mt.sri.com> Nate Williams writes: : Not true at all. Otherwise, the 'hardware' would have to emulate the : functionality of every card that was once in the slot, and respond in : the same fashion. :( OK. Somehow I had it in my head that pccard slots had pins of differing lenght and the short ones were used to trigger interrupts a fraction of a second before the card itself went dead due to the address/data pins going away. This is one reason that I want each driver in its own thread and that the interrupt that says the card is gone to effectively do a longjump to a "You are now gone, don't touch hardware, but cleanup the best you can" routine. However, I'm not sure what this would do to driver complexity. I also know that it may be fraught with problems because you'd need one thread per card and even then some drivers check all units on an interrupt.... Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
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