Re: [PATCH 26/28] drm/nouveau: use the new interator in nv50_wndw_prepare_fb

["Christian König" <ckoenig.leichtzumerken@gmail.com>]

Am 13.10.21 um 16:29 schrieb Daniel Vetter:
> On Tue, Oct 05, 2021 at 01:37:40PM +0200, Christian König wrote:
>> Makes the handling a bit more complex, but avoids the use of
>> dma_resv_get_excl_unlocked().
>>
>> Signed-off-by: Christian König <christian.koenig@amd.com>
>> ---
>>   drivers/gpu/drm/nouveau/dispnv50/wndw.c | 10 +++++++++-
>>   1 file changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/nouveau/dispnv50/wndw.c b/drivers/gpu/drm/nouveau/dispnv50/wndw.c
>> index 8d048bacd6f0..30712a681e2a 100644
>> --- a/drivers/gpu/drm/nouveau/dispnv50/wndw.c
>> +++ b/drivers/gpu/drm/nouveau/dispnv50/wndw.c
>> @@ -539,6 +539,8 @@ nv50_wndw_prepare_fb(struct drm_plane *plane, struct drm_plane_state *state)
>>   	struct nouveau_bo *nvbo;
>>   	struct nv50_head_atom *asyh;
>>   	struct nv50_wndw_ctxdma *ctxdma;
>> +	struct dma_resv_iter cursor;
>> +	struct dma_fence *fence;
>>   	int ret;
>>   
>>   	NV_ATOMIC(drm, "%s prepare: %p\n", plane->name, fb);
>> @@ -561,7 +563,13 @@ nv50_wndw_prepare_fb(struct drm_plane *plane, struct drm_plane_state *state)
>>   			asyw->image.handle[0] = ctxdma->object.handle;
>>   	}
>>   
>> -	asyw->state.fence = dma_resv_get_excl_unlocked(nvbo->bo.base.resv);
>> +	dma_resv_iter_begin(&cursor, nvbo->bo.base.resv, false);
>> +	dma_resv_for_each_fence_unlocked(&cursor, fence) {
>> +		/* TODO: We only use the first writer here */
> Same thing as with the atomic core helper. This is actually broken,
> because for atomic we really do _not_ want to wait for any shared fences.
> Which this will do, if there's no exclusive fence attached.
>
> So upgrading my general concern on this and the atomic helper patch to a
> reject, since I think it's broken.

Since we simply had a misunderstanding with that could I get an rb for 
that now?

Thanks,
Christian.

> -Daniel
>
>> +		asyw->state.fence = dma_fence_get(fence);
>> +		break;
>> +	}
>> +	dma_resv_iter_end(&cursor);
>>   	asyw->image.offset[0] = nvbo->offset;
>>   
>>   	if (wndw->func->prepare) {
>> -- 
>> 2.25.1
>>