From owner-freebsd-stable@FreeBSD.ORG Thu Apr 9 00:39:20 2015 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 0439BB79 for ; Thu, 9 Apr 2015 00:39:20 +0000 (UTC) Received: from sender1.zohomail.com (sender1.zohomail.com [74.201.84.162]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id E5BF2162 for ; Thu, 9 Apr 2015 00:39:19 +0000 (UTC) Received: from WorkBox.Home (184-100-88-41.mpls.qwest.net [184.100.88.41]) by mx.zohomail.com with SMTPS id 1428539951248462.5123016956246; Wed, 8 Apr 2015 17:39:11 -0700 (PDT) Date: Wed, 8 Apr 2015 19:39:08 -0500 From: Bigby James To: freebsd-stable@freebsd.org Subject: i915kms, Xorg, and "Power management discrepency" error Message-ID: <20150409003908.GA2272@WorkBox.Home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 09 Apr 2015 00:39:20 -0000 Ever since rebuilding world from commit r208369 (merging the newer i915kms from HEAD) I've continually received this error in my stdout/logs: > kernel: error: [drm:pid1228:gen6_sanitize_pm] *ERROR* Power management discrepancy: GEN6_RP_INTERRUPT_LIMITS expected 1a0d0000, was 1a000000 The only thing that ever changes is the PID of the process, which always points to Xorg. Under most typical production use this doesn't seem to have any effect, but anytime I watch any sort of video on my production laptop the CPU/GPU temp in my laptop very quickly climbs above 80 degrees celsius. On my multi-purpose server/HTPC, starting an XBMC/Kodi session has the same effect, even if the system is idling (just sitting at the main menu with nothing playing at all). This doesn't stop until I cease video playback on my laptop or kill the Kodi session on the server. Note that the hardware in both machines is identical (yes, the "server" is a laptop), and they're base systems and kernels are synchronized, so whatever is affectng one should be what's affecting the other. I came across an older mailing list thread from February[1] on this same basic subject that didn't seem to go anywhere, but it had the implication that the i915kms module was the cause. That precisely this same error message is present on various Linux forums bolsters the notion that the video driver might be to blame. If anyone has any insight into how to begin debugging this, I'd be grateful. Thanks in advance. - Bigby [1]: http://freebsd.1045724.n5.nabble.com/Weird-ACPI-DRM-messages-on-current-td5986712.html -- "A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools." - Douglas Adams