Date: Wed, 06 Oct 2004 13:08:50 -0600 (MDT) From: "M. Warner Losh" <imp@bsdimp.com> To: jhb@freebsd.org Cc: cvs-all@freebsd.org Subject: Re: cvs commit: src/sys/i386/pci pci_bus.c Message-ID: <20041006.130850.64789190.imp@bsdimp.com> In-Reply-To: <200410061054.42956.jhb@FreeBSD.org> References: <200410060722.i967MwsJ014694@repoman.freebsd.org> <200410061054.42956.jhb@FreeBSD.org>
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In message: <200410061054.42956.jhb@FreeBSD.org>
John Baldwin <jhb@FreeBSD.org> writes:
: On Wednesday 06 October 2004 03:22 am, Warner Losh wrote:
: > imp 2004-10-06 07:22:58 UTC
: >
: > FreeBSD src repository
: >
: > Modified files:
: > sys/i386/pci pci_bus.c
: > Log:
: > For legacy PCI bridges, limit memory allocation to the top 32MB of
: > RAM. Many older, legacy bridges only allow allocation from this
: > range. This only appies to devices who don't have their memory
: > assigned by the BIOS (since we allocate the ranges so assigned
: > exactly), so should have minimal impact.
: >
: > Hoewver, for CardBus bridges (cbb), they rarely get the resources
: > allocated by the BIOS, and this patch helps them greatly. Typically
: > the 'bad Vcc' messages are caused by this problem.
:
: We really should be looking at the SMAP to find out what the real limits of
: PCI space are I think since I think the SMAP includes an entry for PCI memory
: mapped I/O.
Can you point me at the details on how to do this? I'd be absolutely
thrilled to do this correctly, but so far my research has been focused
on the actual host bridges. Sadly, these aren't standardized. If
there's another area I can research, I'd be thrilled.
Warner
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