Re: [PATCH 12/18] drm/amdgpu:use formal register to trigger hdp invalidate

["Zhang, Jerry (Junwei)" <Jerry.Zhang-5C7GfCeVMHo@public.gmane.org>]

On 09/19/2017 04:30 PM, Christian König wrote:
> I don't know why, but the HDP is generally not part of the register spec.

AFAIW, these regs may be used for HW guys to debug some special cases.
Usually they are not suggested to touch formally.
(e.g. GFX cannot access PRT unmap range, but with debug bit set, it could. 
however, it's not normal way.)

Jerry


>
> So you can neither find HDP_DEBUG0 nor HDP_READ_CACHE_INVALIDATE in it as far as
> I know.
>
> Point is that the HDP invalidates it's read cache on any register write (the
> register itself doesn't matter). So far we used the HDP_DEBUG0 register because
> it is unused otherwise, but having a dedicated register just for this job is
> clearly a good idea.
>
> Regards,
> Christian.
>
> Am 19.09.2017 um 09:02 schrieb zhoucm1:
>> >using this register to replace MM_HDP_DEBUG0 is suggested from a HDP HW guys
>>
>> I'm OK with this line.
>>
>> Thanks for explain.
>> David Zhou
>>
>> On 2017年09月19日 15:00, Liu, Monk wrote:
>>> First, I didn't check if windows did this way or not, because I don't sure if
>>> windows is always doing the right thing, e.g. for GFX preemption I didn't
>>> copy windows scheme and we found couple bugs in windows but not in linux ...
>>> So please don't assume we should copy from windows, unless it's solid like a
>>> dead bone
>>>
>>> Second, this register is originally comes from the definition file
>>> "hdp_4_0_offset.h", not recently introduced by me or someone else, and using
>>> this register to replace MM_HDP_DEBUG0 is suggested from a HDP HW guys when
>>> I was working on the PAL/VULKAN preemption hang issue in Orlando, sorry I
>>> missed that guy's name ...
>>>
>>> @Deucher, Alexander do you know who is on hdp hw ? we can confirm with him
>>>
>>>
>>> If you're feeling bad about this change, I can add "if sriov" condition to
>>> all of it, so bare-metal will keep still,  is that okay ?
>>>
>>> BR Monk
>>>
>>>
>>> -----Original Message-----
>>> From: Zhou, David(ChunMing)
>>> Sent: 2017年9月19日 14:51
>>> To: Liu, Monk <Monk.Liu@amd.com>; Koenig, Christian
>>> <Christian.Koenig@amd.com>; amd-gfx@lists.freedesktop.org
>>> Subject: Re: [PATCH 12/18] drm/amdgpu:use formal register to trigger hdp
>>> invalidate
>>>
>>>
>>> Seems the change is more proper, but where do you find
>>> mmHDP_READ_CACHE_INVALIDATE? Could you double check if Windows driver has
>>> changed to use this?
>>> I'm confusing it, since mmHDP_DEBUG0 implementation is from windows as well.
>>> I even don't find mmHDP_READ_CACHE_INVALIDATE in register spec.
>>>
>>> Regards,
>>> David Zhou
>>> On 2017年09月19日 14:46, Liu, Monk wrote:
>>>> What question ? please reply here
>>>>
>>>> -----Original Message-----
>>>> From: Zhou, David(ChunMing)
>>>> Sent: 2017年9月19日 12:25
>>>> To: Liu, Monk <Monk.Liu@amd.com>; Koenig, Christian
>>>> <Christian.Koenig@amd.com>; amd-gfx@lists.freedesktop.org
>>>> Subject: RE: [PATCH 12/18] drm/amdgpu:use formal register to trigger
>>>> hdp invalidate
>>>>
>>>> Please answer my question as I raised in another thread, otherwise I will
>>>> give a NAK on this!
>>>>
>>>> Regards,
>>>> David Zhou
>>>>
>>>> -----Original Message-----
>>>> From: amd-gfx [mailto:amd-gfx-bounces@lists.freedesktop.org] On Behalf
>>>> Of Liu, Monk
>>>> Sent: Tuesday, September 19, 2017 12:04 PM
>>>> To: Koenig, Christian <Christian.Koenig@amd.com>;
>>>> amd-gfx@lists.freedesktop.org
>>>> Subject: RE: [PATCH 12/18] drm/amdgpu:use formal register to trigger
>>>> hdp invalidate
>>>>
>>>> Yeah, vnc1_0 and uvd_v7_0
>>>>
>>>> Thanks
>>>>
>>>> -----Original Message-----
>>>> From: Koenig, Christian
>>>> Sent: 2017年9月18日 19:39
>>>> To: Liu, Monk <Monk.Liu@amd.com>; amd-gfx@lists.freedesktop.org
>>>> Subject: Re: [PATCH 12/18] drm/amdgpu:use formal register to trigger
>>>> hdp invalidate
>>>>
>>>> Yeah, but Vega10 has UVD7 and in uvd_v7_0.c we have:
>>>>
>>>>> static void uvd_v7_0_ring_emit_hdp_invalidate(struct amdgpu_ring
>>>>> *ring) {
>>>>>           amdgpu_ring_write(ring, PACKET0(SOC15_REG_OFFSET(HDP, 0,
>>>>> mmHDP_DEBUG0), 0));
>>>>>           amdgpu_ring_write(ring, 1);
>>>>> }
>>>> That should probably be fixed as well.
>>>>
>>>> Regards,
>>>> Christian.
>>>>
>>>> Am 18.09.2017 um 13:03 schrieb Liu, Monk:
>>>>> Only vega10 has this register
>>>>>
>>>>> -----Original Message-----
>>>>> From: Christian König [mailto:ckoenig.leichtzumerken@gmail.com]
>>>>> Sent: 2017年9月18日 17:20
>>>>> To: Liu, Monk <Monk.Liu@amd.com>; amd-gfx@lists.freedesktop.org
>>>>> Subject: Re: [PATCH 12/18] drm/amdgpu:use formal register to trigger
>>>>> hdp invalidate
>>>>>
>>>>> Am 18.09.2017 um 08:11 schrieb Monk Liu:
>>>>>> Change-Id: I61dc02ea6a450f9acfa3bae07aa20244261f5369
>>>>>> Signed-off-by: Monk Liu <Monk.Liu@amd.com>
>>>>> Reviewed-by: Christian König <christian.koenig@amd.com>
>>>>>
>>>>> Please scan the code once more, we most likely have used mmHDP_DEBUG0 for
>>>>> this at even more places.
>>>>>
>>>>> Christian.
>>>>>
>>>>>> ---
>>>>>>      drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c  | 2 +-
>>>>>>      drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c | 2 +-
>>>>>>      2 files changed, 2 insertions(+), 2 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
>>>>>> b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
>>>>>> index f201510..44960b3 100644
>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
>>>>>> @@ -3549,7 +3549,7 @@ static void gfx_v9_0_ring_emit_hdp_flush(struct
>>>>>> amdgpu_ring *ring)
>>>>>>      static void gfx_v9_0_ring_emit_hdp_invalidate(struct amdgpu_ring *ring)
>>>>>>      {
>>>>>>          gfx_v9_0_write_data_to_reg(ring, 0, true,
>>>>>> -                   SOC15_REG_OFFSET(HDP, 0, mmHDP_DEBUG0), 1);
>>>>>> +                   SOC15_REG_OFFSET(HDP, 0, mmHDP_READ_CACHE_INVALIDATE),
>>>>>> 1);
>>>>>>      }
>>>>>>           static void gfx_v9_0_ring_emit_ib_gfx(struct amdgpu_ring *ring,
>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
>>>>>> b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
>>>>>> index fd7c72a..d5f3848 100644
>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
>>>>>> @@ -398,7 +398,7 @@ static void sdma_v4_0_ring_emit_hdp_invalidate(struct
>>>>>> amdgpu_ring *ring)
>>>>>>      {
>>>>>>          amdgpu_ring_write(ring, SDMA_PKT_HEADER_OP(SDMA_OP_SRBM_WRITE) |
>>>>>> SDMA_PKT_SRBM_WRITE_HEADER_BYTE_EN(0xf));
>>>>>> -    amdgpu_ring_write(ring, SOC15_REG_OFFSET(HDP, 0, mmHDP_DEBUG0));
>>>>>> +    amdgpu_ring_write(ring, SOC15_REG_OFFSET(HDP, 0,
>>>>>> +mmHDP_READ_CACHE_INVALIDATE));
>>>>>>          amdgpu_ring_write(ring, 1);
>>>>>>      }
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>>
>
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