Date: Mon, 03 Jul 2000 10:57:15 -0600 From: Warner Losh <imp@village.org> To: Poul-Henning Kamp <phk@critter.freebsd.dk> Cc: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>, Nick Hibma <n_hibma@calcaphon.com>, cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/sys bus.h bus_private.h src/sys/kern subr_bus.c Message-ID: <200007031657.KAA23779@harmony.village.org> In-Reply-To: Your message of "Mon, 03 Jul 2000 18:52:00 %2B0200." <7213.962643120@critter.freebsd.dk> References: <7213.962643120@critter.freebsd.dk>
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In message <7213.962643120@critter.freebsd.dk> Poul-Henning Kamp writes: : it probably is the correct behaviour for pccard and cardbus to go away : and stay away until replugged. : : It is probably the wrong behaviour for practically any other bus based : technology (cPCI etc). Why is that? When the hardware fails, it is turned off. New hardware is inserted. That new hardware needs to be completely reinitialized from scratch. Some drivers use the softc to tell them where in the initialization process they are. It would be hard to write a driver that could survive the physical removal of the hardware. I'm just not sure what that would gain you. I can see extentions to the newbus framework to support these concepts. It wouldn't be too hard to do this, but I'm not at all sure what it would buy you and the problems appear to be legion. : I have *no* idea which category USB lands in. I'd think it was the same as pccard. You insert, you remove, it is there, it is gone. I don't know if USB devices have unique serial numbers or not. That would be about the only way you could know if the device that came and went was the same one as before. Even then for removable disks this can get extremely tricky (ditto the CF card reader/writers, since the CF cards don't seem to have serial numbers). Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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