Date: Wed, 20 May 1998 11:22:23 -0700 From: Mike Smith <mike@smith.net.au> To: Bruce Evans <bde@zeta.org.au> Cc: current@FreeBSD.ORG, grog@lemis.com, hardware@FreeBSD.ORG, tarkhil@asteroid.svib.ru Subject: Re: IWill and sio, again and again Message-ID: <199805201822.LAA01249@dingo.cdrom.com> In-Reply-To: Your message of "Thu, 21 May 1998 05:15:00 %2B1000." <199805201915.FAA23917@godzilla.zeta.org.au>
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> >> No, I only worked around the problem on one IWill system. The PIC (or > >> something beteween the UART and the PIC) apparently latches rising edges > >> of IRQ signals even for IRQs that are masked in the PIC. > > > >Is this perhaps related to the 'serialized IRQ protocol' that the ACER > >UART claims to support? Some more research indicates that this is a > >"new feature" in the TX and LX chipsets. The descriptions I've been > >able to find of this so far seem to indicate that it might fit the bill. > > >Look for it in the PIIX4 documentation, if you have that. You may need > >to pester Acer for a copy of the 513X datasheet as well. > > Don't have it. I couldn't find your old mail about this. http://www.acerlabs.com for the Acer stuff. If you can't get anything useful out of them, let me know and I'll pursue it. Intel have all their datasheets up at http://developer.intel.com, including the TX stuff. It seems that the deal with the serialised IRQ protocol is that the IRQ is encoded on the PCI bus rather than being an input to the ISA bridge. There may be vagaries in the handling of this. 8( > >> It should not-work even for non-IWill UARTs, since the attach assumes > >> certain values in the cfcr, ier and mcr registers. > > > >That sounds like "I agree". How much effort would be required to make > >the attach assume a completely indeterminate ground state, predicated > >simply on knowing that the port is present? > > 3 lines... plus not more than a few thousand lines to configure it :-). 8) I'll just settle for the attach making no assumptions about the device's state. One thing at a time. -- \\ Sometimes you're ahead, \\ Mike Smith \\ sometimes you're behind. \\ mike@smith.net.au \\ The race is long, and in the \\ msmith@freebsd.org \\ end it's only with yourself. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message
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