Am 29.11.2017 um 13:31 schrieb Oded Gabbay:
> On Wed, Nov 29, 2017 at 1:16 PM, Michel Dänzer <michel at daenzer.net> wrote:
>> On 2017-11-01 09:31 AM, Oded Gabbay wrote:
>>> ok, taken to -next.
>> This change broke the radeon driver on my Kaveri laptop. The gdm login
>> screen works, but logging into the GNOME on Xorg session quickly results
>> in a GPU hang and associated badness, see the attached dmesg.
>>
>> Reverting this change on top of drm-next makes it work again.
>>
>> On a hunch, I've tried reverting commits 62a7b7fbd08e ("drm/radeon:
>> reduce number of free VMIDs and pipes in KV") and 28b57b856b63
>> ("drm/radeon/cik: Don't touch int of pipes 1-7"), but no luck.
>>
>> Any ideas for what else is missing?
>>
>> Note that the amdkfd driver isn't actually active anyway, because I'm
>> disabling the IOMMU. Is it possible that it's still doing or triggering
>> some needed HW setup before it bails in that case?
>>
>>
>> P.S. Assuming we can fix this without reverting, maybe we could also
>> remove rdev->grbm_idx_mutex again?
>>
>> --
>> Earthling Michel Dänzer | http://www.amd.com
>> Libre software enthusiast | Mesa and X developer
> Hi Michel,
> Even without IOMMU, amdkfd will initialize the module and internal
> structures per device, up to the point where it tries to register a
> callback with the iommu driver.
> If IOMMU is disabled, it will fail then with the following error
> message (in dmesg): "error getting iommu info. is the iommu enabled?"
>
> Having said that, it doesn't initialize anything in the device H/W
> itself, so I find this very weird.
>
> I looked at the patch itself again and I don't see anything suspicious.
>
> I'll try to resurrect my Kaveri machine to check this, but it will
> take some time.
My best guess is that there is something broken with the VMID handling
on Radeon.
I have a Kaveri running amdgpu as one of my test systems here and
switching to radeon for a test should be trivial.
Going to give that a try later today if I have time.
Christian.
>
> Oded
