Date: Wed, 15 Jun 2011 09:48:09 -0700 From: Nate Lawson <nate@root.org> To: John Baldwin <jhb@freebsd.org> Cc: acpi@freebsd.org Subject: Re: Only attach device_t objects to ACPI devices with a _HID Message-ID: <DB0F2A34-C457-4372-8A20-1F32EE3A66BD@root.org> In-Reply-To: <201106150957.58049.jhb@freebsd.org>
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On Jun 15, 2011, at 6:57 AM, John Baldwin wrote: > What I am proposing to do is to change the ACPI bus driver to only add > device_t objects for Device() nodes that have a _HID or _CID. This should not > break any devices that have a current driver, but it will avoid having ACPI > attach to PCI devices. This does mean that _CRS is currently ignored for PCI > devices. My feeling on that is that if we do feel that is important to > reserve those resources, we should handle that in the ACPI PCI bus driver > itself instead (it can examine _CRS for those devices and allocate resources > if we so choose). While this should be fine for legacy devices, I do worry about other synthetic devices, such as CPUs, NUMA zones, etc. Would it be better just not to attach acpi device_t's to any nodes under PCI busses? Also, it's still possible some PCI devices would have a CID, so you'd still have to handle this case, right? > It does strike me as odd that BIOSes are assigning resources to PCI devices > via _CRS and I wonder if it is truly valid or it it should just be ignored. I think I remember some BIOSes hooking _CRS to do some late allocations. It's bad behavior, of course, and closely ties their allocation scheme to the order that WIndows traversed the acpi device tree. -Natehome | help
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