RE: amd-iommu: can't boot with amdgpu, AMD-Vi: Completion-Wait loop timed out

From: "Nath, Arindam" <Arindam.Nath-5C7GfCeVMHo@public.gmane.org>
To: "'joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org'"
	<joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>,
	"Deucher,
	Alexander" <Alexander.Deucher-5C7GfCeVMHo@public.gmane.org>
Cc: Chris Chiu <chiu-6IF/jdPJHihWk0Htik3J/w@public.gmane.org>,
	"amd-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org"
	<amd-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org>,
	Daniel Drake <drake-6IF/jdPJHihWk0Htik3J/w@public.gmane.org>,
	"iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org"
	<iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>,
	Alex Deucher
	<alexdeucher-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Linux Upstreaming Team
	<linux-6IF/jdPJHihWk0Htik3J/w@public.gmane.org>
Subject: RE: amd-iommu: can't boot with amdgpu, AMD-Vi: Completion-Wait loop timed out
Date: Tue, 21 Mar 2017 16:14:37 +0000	[thread overview]
Message-ID: <MWHPR12MB15187F29F97E9920E3EF0AA69C3D0@MWHPR12MB1518.namprd12.prod.outlook.com> (raw)
In-Reply-To: <20170321161056.GE29659-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>

>-----Original Message-----
>From: 'joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org' [mailto:joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org]
>Sent: Tuesday, March 21, 2017 9:41 PM
>To: Deucher, Alexander
>Cc: Alex Deucher; Daniel Drake; Chris Chiu; amd-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org;
>Nath, Arindam; iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org; Suthikulpanit, Suravee;
>Linux Upstreaming Team
>Subject: Re: amd-iommu: can't boot with amdgpu, AMD-Vi: Completion-Wait
>loop timed out
>
>On Tue, Mar 21, 2017 at 04:01:53PM +0000, Deucher, Alexander wrote:
>> It seems to only affect Stoney systems, but not others (Carrizo,
>> Bristol, etc.).  Maybe we could just disable it on Stoney until we
>> root cause it.
>
>Completion-wait loop timeouts indicate something is seriously wrong. How
>can I detect whether I am running on a 'Stoney' system?
>
>Other question, a shot into the dark, does the GPU on these systems have
>ATS? Probably yes, as they are likely HSA compatible.

The GPU on Stoney supports ATS.

Thanks,
Arindam

>
>
>	Joerg