Re: [PATCH v3 4/9] drm/panthor: Don't call drm_gpuvm_bo_extobj_add() if the object is private

[Liviu Dudau <liviu.dudau@arm.com>]

On Wed, Feb 11, 2026 at 09:03:38AM +0100, Boris Brezillon wrote:
> drm_gpuvm_bo_extobj_add() is a NOP if the object is private, but it
> forces us to take/release the VM resv lock, so let's do that only when
> we know the object can be shared.
> 
> v3:
> - New commit
> 
> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>

Best regards,
Liviu

> ---
>  drivers/gpu/drm/panthor/panthor_mmu.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
> index ba3b7c93303c..99c794c429ca 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -1284,9 +1284,11 @@ static int panthor_vm_prepare_map_op_ctx(struct panthor_vm_op_ctx *op_ctx,
>  	}
>  
>  	/* Insert BO into the extobj list last, when we know nothing can fail. */
> -	dma_resv_lock(panthor_vm_resv(vm), NULL);
> -	drm_gpuvm_bo_extobj_add(op_ctx->map.vm_bo);
> -	dma_resv_unlock(panthor_vm_resv(vm));
> +	if (bo->base.base.resv != panthor_vm_resv(vm)) {
> +		dma_resv_lock(panthor_vm_resv(vm), NULL);
> +		drm_gpuvm_bo_extobj_add(op_ctx->map.vm_bo);
> +		dma_resv_unlock(panthor_vm_resv(vm));
> +	}
>  
>  	return 0;
>  
> -- 
> 2.52.0
> 

-- 
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