Re: [igt-dev] [PATCH i-g-t] lib/batchbuffer: Ensure obj.alignment is zeroed for softpinning

["Dixit, Ashutosh" <ashutosh.dixit@intel.com>]

On Thu, 28 Jul 2022 05:06:20 -0700, Zbigniew Kempczyński wrote:
>
> Passing obj.alignment doesn't make sense for softpinning as offsets
> are under full control of allocator.

Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>

> Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
> Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
> ---
>  lib/intel_batchbuffer.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/lib/intel_batchbuffer.c b/lib/intel_batchbuffer.c
> index 36cb55048d..ef1b594771 100644
> --- a/lib/intel_batchbuffer.c
> +++ b/lib/intel_batchbuffer.c
> @@ -1346,7 +1346,6 @@ __intel_bb_create(int i915, uint32_t ctx, uint32_t size, bool do_relocs,
>
>	igt_assert(ibb);
>
> -	ibb->allows_obj_alignment = gem_allows_obj_alignment(i915);
>	ibb->uses_full_ppgtt = gem_uses_full_ppgtt(i915);
>	ibb->devid = intel_get_drm_devid(i915);
>	ibb->gen = intel_gen(ibb->devid);
> @@ -1359,6 +1358,13 @@ __intel_bb_create(int i915, uint32_t ctx, uint32_t size, bool do_relocs,
>	if (!ibb->uses_full_ppgtt)
>		do_relocs = true;
>
> +	/*
> +	 * For softpin mode allocator has full control over offsets allocation
> +	 * so we want kernel to not interfere with this.
> +	 */
> +	if (do_relocs)
> +		ibb->allows_obj_alignment = gem_allows_obj_alignment(i915);
> +
>	/* Use safe start offset instead assuming 0x0 is safe */
>	start = max_t(uint64_t, start, gem_detect_safe_start_offset(i915));
>
> --
> 2.34.1
>