Date: Tue, 05 Jul 2011 15:19:32 +0300 From: Andriy Gapon <avg@FreeBSD.org> To: Vitaly Magerya <vmagerya@gmail.com> Cc: freebsd-acpi@FreeBSD.org Subject: Re: (Missing) power states of an Atom N455-based netbook Message-ID: <4E130154.9080809@FreeBSD.org> In-Reply-To: <CAL409Kw=rUnm9D56KvYiFWiU-bp59KqKnPcUXL38rZsW_Qh8AQ@mail.gmail.com> References: <BANLkTim%2B1UwquMJ32WP8wZBGkYxPv78MLA@mail.gmail.com> <4E05EB91.9090509@FreeBSD.org> <BANLkTi=dyNx=TjyEqYMhSkRtddjVA4nAtw@mail.gmail.com> <4E0862A0.7060405@FreeBSD.org> <BANLkTikmVUtLyANBSqYb%2BL-xkwQ4Zo51Eg@mail.gmail.com> <4E09BADF.7050702@FreeBSD.org> <BANLkTin_%2BZH%2Bo7rdR9ijHMtrXcSdH9ZSdQ@mail.gmail.com> <4E0A41C8.3000904@FreeBSD.org> <BANLkTikwgy%2BKuA5E5zXQKGT-eyV35YAVag@mail.gmail.com> <4E0CE158.6030804@FreeBSD.org> <BANLkTinRY-h%2BkpXtwWJ_L86qVRdoynFSdg@mail.gmail.com> <4E0DB58F.4070906@FreeBSD.org> <CAL409Kw=rUnm9D56KvYiFWiU-bp59KqKnPcUXL38rZsW_Qh8AQ@mail.gmail.com>
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on 02/07/2011 23:30 Vitaly Magerya said the following: > Andriy Gapon <avg@freebsd.org> wrote: >>> VDRV: 00 -> 01 >> >> Looks like this variable should tell if OS has ACPI Video driver, to be precise >> if _BCL method was invoked at least once. >> Looks like in your case the driver doesn't attach for some reason?.. > > I don't have acpi_video loaded (it's not loaded by default). If I > do load it, VDRV indeed becomes 1 (brightness controls that acpi_video > exposes don't work though; this appears to be a known problem with > Samsung laptops). This might warrant a separate investigation and a PR if we don't have one already. Not sure if I could be of help with it, though. >> Actually, it seems that they have them simply hardcoded: >> http://lxr.linux.no/#linux+v2.6.39/drivers/idle/intel_idle.c#L171 >> I am not sure how to check on Linux which cpuidle driver is being used. If you >> know, could please check that? And if the driver is intel_idle, then there is >> no mystery, they use those hardcoded values. > > I think the mystery is solved then: > > $ cat /sys/devices/system/cpu/cpuidle/current_driver > intel_idle Possible courses of action: 1. Do nothing and leave you with your workaround. 2. Provide intel_idle-like driver for FreeBSD. I don't like this approach for reasons I've stated before. 3. Try to make FreeBSD smarter with respect to dynamically changing C-states. I think it would be useful if we received a devd notifications about C-state reconfiguration. Then we could execute /etc/rc.d/power_profile to account for the new configuration. -- Andriy Gapon
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