Date: Mon, 26 Oct 2009 09:32:48 -0700 From: Marcel Moolenaar <xcllnt@mac.com> To: John Baldwin <jhb@freebsd.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r198431 - head/sys/dev/pci Message-ID: <8082A638-C5BA-42F9-8C2E-DA31EF084840@mac.com> In-Reply-To: <200910260837.23479.jhb@freebsd.org> References: <200910232253.n9NMr10R074584@svn.freebsd.org> <200910260837.23479.jhb@freebsd.org>
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On Oct 26, 2009, at 5:37 AM, John Baldwin wrote: >> Log: >> BIOSes, buggy or otherwise, are i386 or amd64 specific. >> Have the early USB takeover enabled for i386 and amd64 >> by default. >> This also avoids a panic on PowerPC where the resource >> isn't released properly and we find a busy resource >> when the USB host controller wants to allocate it... > > Presumably such systems won't set the 'BIOS owned' bit in the their > legacy > support registers in which case these routines are NOPs (they just > read the > register, see the bit is clear, and exit). The resource bug sounds > like a > real one that should be fixed and would probably affect any x86 > systems who > have USB disabled in the BIOS, so that should be fixed rather than > papered > over. Please revert. *sigh* The change was made because 1) doing this as part of the PCI code is unnecessary for non-PC HW, and 2) it's entirely untested on non-PC HW and the gratuitous change can therefore only do harm -- he, guess what, it did do harm. Unless people fix the resource stuff this change cannot be reverted. After the resource fix has gone in, I still object to this being reverted on grounds of gratuitous code bloat. I say this with ARM, MIPS and PowerPC/Book-E in mind. > Note that the legacy support register stuff is part of the uhci/ohci/ > ehci > specifications, and that the code to frob it has been part of the same > drivers since their inception. If it had been an actual problem > then it > would have been disabled back when USB was enabled for other > architectures. This is entirely besides the point... -- Marcel Moolenaar xcllnt@mac.com
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