From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ilia Mirkin Subject: Re: Kernel Freeze with American Megatrends BIOS Date: Tue, 30 Aug 2016 11:44:38 -0400 Message-ID: References: <004c7dbe-2014-c691-29d1-7a45f3b73dfa@desertbit.com> <20160829160210.GA24451@localhost> <1cca943f-eab4-4054-4a13-31370d7ae057@desertbit.com> <20160829190737.GA4053@localhost> <20160829235403.GA14177@localhost> <1d1bfdc2-f23d-9816-e4e3-ae676105dc39@desertbit.com> <20160830130634.GA16426@localhost> <735da66c-aaf3-8c27-2d59-f62e8c85d3aa@desertbit.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Received: from mail-it0-f49.google.com ([209.85.214.49]:32791 "EHLO mail-it0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932267AbcH3Pok (ORCPT ); Tue, 30 Aug 2016 11:44:40 -0400 In-Reply-To: <735da66c-aaf3-8c27-2d59-f62e8c85d3aa@desertbit.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Roland Singer Cc: Emil Velikov , Bjorn Helgaas , Linux PCI , "Linux-Kernel@Vger. Kernel. Org" , ML dri-devel , "linux-acpi@vger.kernel.org" On Tue, Aug 30, 2016 at 11:25 AM, Roland Singer wrote: > I tried these scenarios: > > 1. Booted the system without the bbswitch module. The nouveau module > was loaded and is responsible for the power management of the GPU. > The graphical session freezes after some minutes... > > 2. Booted the system without bbswitch and with nouveau blacklisted. > Manually loaded bbswitch to switch off the discrete GPU. > Same freeze after a while or by explicitly obtaining the GPU state. > > Is there a possibility to switch off the discrete card without bbswitch? > If this is possible, then I could test this without nouveau and bbswitch > at all. If the system hangs, then it is not the video driver nor bbswitch. You can use acpi_call (a random search points to https://github.com/mkottman/acpi_call, but I don't know if that's the "official" version) - need to find the right method to call, but that's basically all it takes to acpi-suspend a gpu. Separately, there was a recent fix to ... something, including but not limited to nouveau, involving hangs on gpu suspend on newer laptops. I don't think it's upstream yet. Look for patches from Lukas Wunner. -ilia