Date: Sun, 18 Sep 2005 13:45:18 -0600 (MDT) From: "M. Warner Losh" <imp@bsdimp.com> To: nate@root.org Cc: cvs-src@freebsd.org, joao.barros@gmail.com, src-committers@freebsd.org, cvs-all@freebsd.org Subject: Re: cvs commit: src/sys/dev/pci pci.c Message-ID: <20050918.134518.31977329.imp@bsdimp.com> In-Reply-To: <432D9F4B.9080902@root.org> References: <200509111928.j8BJSWci066427@repoman.freebsd.org> <70e8236f0509180715406f1f31@mail.gmail.com> <432D9F4B.9080902@root.org>
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In message: <432D9F4B.9080902@root.org>
Nate Lawson <nate@root.org> writes:
: Joao Barros wrote:
: > On 9/11/05, Warner Losh <imp@freebsd.org> wrote:
: >
: >>imp 2005-09-11 19:28:31 UTC
: >>
: >> FreeBSD src repository
: >>
: >> Modified files: (Branch: RELENG_6)
: >> sys/dev/pci pci.c
: >> Log:
: >> Change the default of pci_do_powerstate to 0, per request from re@.
: >> The number of raid controllers that violate the WHQL seems to be
: >> growing in number and not isolated to old versions as previously
: >> thought. Though the numbers of these seen in the wild is still
: >> relatively small, they hang the system when parts of their devices are
: >> powered down. The one area that these parts appear often are in the
: >> higher end servers. As such, be conservative about powering down
: >> devices that have no driver attached by default. Until a better
: >> approach is proven in current, this is the prudent choice.
: >>
: >> Laptop users wishing the benefits of powering down devices with no
: >> drivers will now need to set hw.pci.do_powerstate=1 in their
: >> /boot/loader.conf file. Some users will have devices that will
: >> prevent this setting (hence the need to make it default 0).
: >>
: >> Approved by: re@ (scottl)
: >>
: >> Revision Changes Path
: >> 1.292.2.2 +2 -2 src/sys/dev/pci/pci.c
: >
: > I was reading the Release Notes for 6.0 on
: > http://www.freebsd.org/relnotes/6-STABLE/relnotes/i386/article.html
: > and noticed:
: >
: > 2.2.2 Hardware Support
: >
: > The acpi(4) driver now turns the ACPI and PCI devices off or to a
: > lower power state when suspending, and back on again when resuming.
: > This behavior can be disabled by setting the debug.acpi.do_powerstate
: > and hw.pci.do_powerstate sysctls to 0.
: >
: > Given this is the same tunable you changed back to 0 by default, does
: > that "when resuming" has anything to do with this last commit? If so,
: > it could still be mentioned the other way around, allowing people
: > wanting to, to enable the tunable :)
:
: You bring up a different point also, which is that ACPI should probably
: be set to match this same default for release.
Actually, all that the do_powerstate stuff in pci land does is turn
off the devices when no driver is attached. We always turn them back
on on resume.
Warner
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