From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from nm24-vm2.access.bullet.mail.bf1.yahoo.com ([216.109.115.177]:52541 "EHLO nm24-vm2.access.bullet.mail.bf1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751582AbaJKTha (ORCPT ); Sat, 11 Oct 2014 15:37:30 -0400 From: Shawn Starr To: Bjorn Helgaas Cc: Kernel development list , "linux-pci@vger.kernel.org" Subject: Re: [Bulk] Re: [3.16-rcX][pciehp][radeon] PCIe HotPlug conflicts with radeon GPU Date: Sat, 11 Oct 2014 15:37:09 -0400 Message-ID: <2298090.n99M7dPPE3@segfault> In-Reply-To: References: <2354837.kuMZPK0Y1Q@segfault> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: linux-pci-owner@vger.kernel.org List-ID: On September 11, 2014 04:26:21 PM Bjorn Helgaas wrote: > [+cc linux-pci] > > On Sat, Aug 2, 2014 at 10:02 AM, Shawn Starr wrote: > > Hello devs, > > > > There are two issues I am encountering with the PCIe Hotplug driver on my > > Lenovo Laptop (W500). I note this goes back further than 3.15. > > > > It is noted here: > > http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id= > > f244d8b623dae7a7bc695b0336f67729b95a9736 > > https://bugzilla.kernel.org/show_bug.cgi?id=79701 > > > > And my open bug here: > > https://bugzilla.kernel.org/show_bug.cgi?id=77261 > > > > 1) If I enable the device to use both the integrated and discrete GPU, > > pciehp will decide to force unload radeon because it puts itself into a > > power saving state, fails back to the Intel integrated GPU in this case > > unless I tell radeon.ko to runpm=0 (no power management, then pciehp wont > > touch it). > > > > 2) If the Radeon GPU resets and you use pci_reset=1 for kernel module > > option, pciehp decides to force unload radeon even though the GPU is > > trying to setup after failing. > > > > Kernel I am using right now: 3.16.0-0.rc7.git3.1.fc21.x86_64 (about to > > boot into snapshot kernel-core-3.16.0-0.rc7.git4.1.fc21.x86_64) > Hi Shawn, > > Thanks for the report and sorry that it got dropped. But I see you're > cc'd on https://bugzilla.kernel.org/show_bug.cgi?id=79701, so you've > probably seen the work there. If you can try out the patches I just > posted, that would be great. > > Bjorn Hi Bjorn, For #1) This is fixed in linux-next (tracking 3.18.0-0.rc0.git1.2.fc22.1.x86_64 nondebug kernel for Fedora). PCIe HotPlug no longer unloads radeon. For this bugzilla report we can close it. #2) This still has weird results however, radeon.hard_reset=1 is experimental and while it attempts to reset GPU, PCIe HotPlug seems to interact in this. This can be tested by adding to grub command line radeon.hard_reset=1. When X has started up, trigger a reset by cat /sys/kernel/debug/dri/#/radeon_gpu_reset. It will output 0, cat it again will show 1. Attempt to drag a window. The this will trigger a GPU reset, but fail to recover, its unknown if PCIe HotPlug is preventing a proper reset or not but there is pciehp calls in the stack trace. Thanks, Shawn