[Intel-gfx] [PATCH 2/3] i915/perf: Do not add ggtt offset to hw_tail

[Dixit, Ashutosh]

On Wed, 31 May 2023 16:56:33 -0700, Umesh Nerlige Ramappa wrote:
>
> ggtt offset for hw_tail is not required for the calculations, so drop
> it.
>
> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_perf.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
> index 29124dcba8e2..beb1269422ca 100644
> --- a/drivers/gpu/drm/i915/i915_perf.c
> +++ b/drivers/gpu/drm/i915/i915_perf.c
> @@ -565,7 +565,7 @@ static bool oa_buffer_check_unlocked(struct i915_perf_stream *stream)
>	partial_report_size %= report_size;
>
>	/* Subtract partial amount off the tail */
> -	hw_tail = gtt_offset + OA_TAKEN(hw_tail, partial_report_size);
> +	hw_tail = OA_TAKEN(hw_tail, partial_report_size);
>
>
>	/* NB: The head we observe here might effectively be a little
> @@ -575,7 +575,6 @@ static bool oa_buffer_check_unlocked(struct i915_perf_stream *stream)
>	head = stream->oa_buffer.head - gtt_offset;
>	aged_tail = stream->oa_buffer.tail - gtt_offset;
>
> -	hw_tail -= gtt_offset;

Yes gtt_offset addition/subtraction is now redundant after we drop the if-else.

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


>	tail = hw_tail;
>
>		/* Walk the stream backward until we find a report with report
> --
> 2.36.1
>