Re: [PATCH 2/3] drm/xe/xe_oa: Avoid checking and setting fields in the OA report

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

On Fri, 21 Aug 2026 15:23:41 -0700, Umesh Nerlige Ramappa wrote:
>
> @@ -260,7 +224,7 @@ static bool mert_wa_14026633728(struct xe_oa_stream *s)
>  static bool xe_oa_buffer_check_unlocked(struct xe_oa_stream *stream)
>  {
>	u32 gtt_offset = xe_bo_ggtt_addr(stream->oa_buffer.bo);
> -	u32 tail, hw_tail, partial_report_size, available;
> +	u32 hw_tail, partial_report_size, available;
>	int report_size = stream->oa_buffer.format->size;
>	unsigned long flags;
>
> @@ -280,29 +244,7 @@ static bool xe_oa_buffer_check_unlocked(struct xe_oa_stream *stream)
>	/* Subtract partial amount off the tail */
>	hw_tail = xe_oa_circ_diff(stream, hw_tail, partial_report_size);
>
> -	tail = hw_tail;
> -
> -	/*
> -	 * Walk the stream backward until we find a report with report id and timestamp
> -	 * not 0. We can't tell whether a report has fully landed in memory before the
> -	 * report id and timestamp of the following report have landed.
> -	 *
> -	 * This is assuming that the writes of the OA unit land in memory in the order
> -	 * they were written.  If not : (╯°□°）╯︵ ┻━┻
> -	 */
> -	while (xe_oa_circ_diff(stream, tail, stream->oa_buffer.tail) >= report_size) {
> -		if (oa_report_id(stream, tail) || oa_timestamp(stream, tail))
> -			break;
> -
> -		tail = xe_oa_circ_diff(stream, tail, report_size);
> -	}
> -
> -	if (xe_oa_circ_diff(stream, hw_tail, tail) > report_size)
> -		drm_dbg(&stream->oa->xe->drm,
> -			"unlanded report(s) head=0x%x tail=0x%x hw_tail=0x%x\n",
> -			stream->oa_buffer.head, tail, hw_tail);
> -
> -	stream->oa_buffer.tail = tail;
> +	stream->oa_buffer.tail = hw_tail;

This line is added here and then is modified in Patch 3. So maybe we should
not add this line here, just add the line in Patch 3? And just delete line
in this patch? So this patch will only contain code deletion.

Also take care of the issue reported by sashiko:

- [Low] The macro `oa_report_header_64bit` is left defined but is completely unused after its only callers were removed.

Apart from these nits, this is:

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