Date: Thu, 10 Mar 2016 19:19:06 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 207889] Significant increase in Sandy Bridge laptop power consumption after Linux 3.8 i915 update Message-ID: <bug-207889-8@https.bugs.freebsd.org/bugzilla/>
next in thread | raw e-mail | index | archive | help
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D207889 Bug ID: 207889 Summary: Significant increase in Sandy Bridge laptop power consumption after Linux 3.8 i915 update Product: Base System Version: 11.0-CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: emaste@freebsd.org As reported on the FreeBSD-x11 mailing list - adding this PR to keep track = of the details. I updated my regular laptops to HEAD after this commit and have discovered = that the power consumption seems to have increased significantly. This is on a Thinkpad X220 (Sandy Bridge). With a r286085 kernel installed on the disk it and reports 11W while idle a= t a vt(4) console without the driver loaded. After loading i915kms.ko but still= at the vt(4) console that increased to 14W. Booting from a USB stick at r296565 showed 13W initially, rising to 25W aft= er loading i915kms.ko. These numbers were obtained from "acpiconf -i0" while running on battery, f= rom the "Present rate" value near the bottom of the output. In each case I let = the laptop wait in the same state for a couple of minutes and then compared 3 o= r 4 results over 20 seconds or so to see that the power consumption appeared to have settled. There are related reports on Linux although those specifically deal with increased power consumption after a suspend-resume cycle. Links: https://bugs.freedesktop.org/show_bug.cgi?id=3D54089 https://bugzilla.kernel.org/show_bug.cgi?id=3D58971 https://patchwork.kernel.org/patch/2827634/ (patch v1) https://github.com/torvalds/linux/commit/7dcd2677ea912573d9ed4bcd629b0023b2= d11505 https://github.com/torvalds/linux/commit/d11a96d0a4927e8948a6e92a581779f961= d9745b I have the two patches referenced there in a code review (https://reviews.freebsd.org/D5599) although it does not address the increa= sed consumption immediately after loading i915kms.ko, and after further testing= it seems I see normal power consumption after suspend-resume with and without = the patch. --=20 You are receiving this mail because: You are the assignee for the bug.=
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-207889-8>