[PATCH 18/19] drm/amdgpu: Disable GFX PG on CZ

[Deucher, Alexander]

> -----Original Message-----
> From: amd-gfx [mailto:amd-gfx-bounces at lists.freedesktop.org] On Behalf
> Of Felix Kuehling
> Sent: Friday, August 11, 2017 8:40 PM
> To: StDenis, Tom; amd-gfx at lists.freedesktop.org; oded.gabbay at gmail.com
> Subject: Re: [PATCH 18/19] drm/amdgpu: Disable GFX PG on CZ
> 
> With the next change that adds programming of RLC_CP_SCHEDULERS it's a
> VM fault and hard hang during boot, just after HWS initialization.
> Without that change it's only a MEC hang when the first application
> tries to create a user mode queue.

I wonder if there is an issue changing RLC_CP_SCHEDULERS?  Maybe we need to setup KIQ and HIQ at the same time?  I'm not sure to what extent HIQ was validated with GFX PG.  I don't think HIQ is used on other OSes.  We may need some KCL options for this depending on what we are delivering (ROCm vs. OEM preload) or longer term maybe we can add some callback to disable PG while KFD is active.  Anyway, patch is:
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

Alex

> 
> Regards,
>   Felix
> 
> On 2017-08-11 08:08 PM, StDenis, Tom wrote:
> > Hmm, I'd still be careful about disabling GFX PG since we may fail to meet
> energy star requirements.
> >
> > Does the system hard hang or simply GPU hang?
> >
> > Tom
> >
> > ________________________________________
> > From: Kuehling, Felix
> > Sent: Friday, August 11, 2017 19:56
> > To: StDenis, Tom; amd-gfx at lists.freedesktop.org;
> oded.gabbay at gmail.com
> > Subject: Re: [PATCH 18/19] drm/amdgpu: Disable GFX PG on CZ
> >
> > Yes, I'm up-to-date. KFD doesn't use the KIQ to map the HIQ. And HIQ
> > maps all our other queues (unless we're disabling the hardware scheduler).
> >
> > Regards,
> >   Felix
> >
> >
> > On 2017-08-11 07:45 PM, StDenis, Tom wrote:
> >> Hi Felix,
> >>
> >> I'm assuming your tree is up to date with amd-staging-4.11 or 4.12 but we
> did previously have issues with compute rings if PG was enabled (specifically
> CGCG + PG) on Carrizo.  Then David committed some KIQ upgrades and it
> started working properly.
> >>
> >> Could that be related?  Because GFX PG "should work" on Carrizo is the
> official line last I heard from the GFX IP team.
> >>
> >> Cheers,
> >> Tom
> >> ________________________________________
> >> From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> on behalf of
> Felix Kuehling <Felix.Kuehling at amd.com>
> >> Sent: Friday, August 11, 2017 17:56
> >> To: amd-gfx at lists.freedesktop.org; oded.gabbay at gmail.com
> >> Cc: Kuehling, Felix
> >> Subject: [PATCH 18/19] drm/amdgpu: Disable GFX PG on CZ
> >>
> >> It's causing problems with user mode queues and the HIQ, and can
> >> lead to hard hangs during boot after programming RLC_CP_SCHEDULERS.
> >>
> >> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
> >> ---
> >>  drivers/gpu/drm/amd/amdgpu/vi.c | 3 +--
> >>  1 file changed, 1 insertion(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/vi.c
> b/drivers/gpu/drm/amd/amdgpu/vi.c
> >> index 18bb3cb..495c8a3 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/vi.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/vi.c
> >> @@ -1029,8 +1029,7 @@ static int vi_common_early_init(void *handle)
> >>                 /* rev0 hardware requires workarounds to support PG */
> >>                 adev->pg_flags = 0;
> >>                 if (adev->rev_id != 0x00 || CZ_REV_BRISTOL(adev->pdev-
> >revision)) {
> >> -                       adev->pg_flags |= AMD_PG_SUPPORT_GFX_PG |
> >> -                               AMD_PG_SUPPORT_GFX_SMG |
> >> +                       adev->pg_flags |= AMD_PG_SUPPORT_GFX_SMG |
> >>                                 AMD_PG_SUPPORT_GFX_PIPELINE |
> >>                                 AMD_PG_SUPPORT_CP |
> >>                                 AMD_PG_SUPPORT_UVD |
> >> --
> >> 2.7.4
> >>
> >> _______________________________________________
> >> amd-gfx mailing list
> >> amd-gfx at lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
> 
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