[Mesa-dev] [PATCH] radeonsi: don't set DATA_FORMAT if ADD_TID_ENABLE is set on VI (v2)

[Marek Olšák]

After some testing, I realized this patch causes problems. DATA_FORMAT
with ADD_TID=1 means STRIDE[14:17] only if the instruction is untyped
MUBUF, but Mesa only uses ADD_TID with typed MUBUF (tbuffer in
particular).

Marek

On Thu, Oct 1, 2015 at 10:27 AM, Christian König
<deathsimple at vodafone.de> wrote:
> On 01.10.2015 05:44, Michel Dänzer wrote:
>>
>> On 01.10.2015 04:11, Marek Olšák wrote:
>>>
>>> From: Marek Olšák <marek.olsak at amd.com>
>>>
>>> This can cause incorrect address calculations and hangs.
>>>
>>> v2: do it properly
>>>
>>> Cc: mesa-stable at lists.freedesktop.org
>>> Tested-and-Reviewed-by: Christian König <christian.koenig at amd.com>
>>> ---
>>>   src/gallium/drivers/radeonsi/si_descriptors.c | 9 ++++++++-
>>>   1 file changed, 8 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/src/gallium/drivers/radeonsi/si_descriptors.c
>>> b/src/gallium/drivers/radeonsi/si_descriptors.c
>>> index b07ab3b..b56219a 100644
>>> --- a/src/gallium/drivers/radeonsi/si_descriptors.c
>>> +++ b/src/gallium/drivers/radeonsi/si_descriptors.c
>>> @@ -619,11 +619,18 @@ void si_set_ring_buffer(struct pipe_context *ctx,
>>> uint shader, uint slot,
>>>                           S_008F0C_DST_SEL_Z(V_008F0C_SQ_SEL_Z) |
>>>                           S_008F0C_DST_SEL_W(V_008F0C_SQ_SEL_W) |
>>>
>>> S_008F0C_NUM_FORMAT(V_008F0C_BUF_NUM_FORMAT_FLOAT) |
>>> -
>>> S_008F0C_DATA_FORMAT(V_008F0C_BUF_DATA_FORMAT_32) |
>>>                           S_008F0C_ELEMENT_SIZE(element_size) |
>>>                           S_008F0C_INDEX_STRIDE(index_stride) |
>>>                           S_008F0C_ADD_TID_ENABLE(add_tid);
>>>   +             /* If ADD_TID_ENABLE is set on VI, DATA_FORMAT specifies
>>> +                * STRIDE bits [14:17]
>>> +                */
>>> +               if (sctx->b.chip_class >= VI && add_tid)
>>> +                       desc[3] |= S_008F0C_DATA_FORMAT(stride >> 14);
>>> +               else
>>> +                       desc[3] |=
>>> S_008F0C_DATA_FORMAT(V_008F0C_BUF_DATA_FORMAT_32);
>>
>> The beginning of the function has:
>>
>>         /* The stride field in the resource descriptor has 14 bits */
>>         assert(stride < (1 << 14));
>>
>> So the if-branch is dead code in a non-release build. Would be nice if
>> that could be reconciled somehow, but I'm fine with doing it in a
>> follow-up change. Either way, this change is
>>
>> Reviewed-by: Michel Dänzer <michel.daenzer at amd.com>
>
>
> Yeah, agree. Might be nice if someone can come up with a test for this, but
> I don't think this is absolutely necessary.
>
> For now the patch is Reviewed-by: Christian König <christian.koenig at amd.com>
>
> Regards,
> Christian.