Instead of aged_tail use an iterator that starts from the hw_tail and
goes backward until the oa_buffer.tail looking for valid reports.
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_perf.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index beb1269422ca..39f5ab1911c8 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -543,7 +543,7 @@ static bool oa_buffer_check_unlocked(struct i915_perf_stream *stream)
{
u32 gtt_offset = i915_ggtt_offset(stream->oa_buffer.vma);
int report_size = stream->oa_buffer.format->size;
- u32 head, tail, aged_tail;
+ u32 head, tail, iter;
unsigned long flags;
bool pollin;
u32 hw_tail;
@@ -567,15 +567,14 @@ static bool oa_buffer_check_unlocked(struct i915_perf_stream *stream)
/* Subtract partial amount off the tail */
hw_tail = OA_TAKEN(hw_tail, partial_report_size);
-
/* NB: The head we observe here might effectively be a little
* out of date. If a read() is in progress, the head could be
* anywhere between this head and stream->oa_buffer.tail.
*/
head = stream->oa_buffer.head - gtt_offset;
- aged_tail = stream->oa_buffer.tail - gtt_offset;
+ tail = stream->oa_buffer.tail - gtt_offset;
- tail = hw_tail;
+ iter = hw_tail;
/* Walk the stream backward until we find a report with report
* id and timestmap not at 0. Since the circular buffer pointers
@@ -588,23 +587,23 @@ static bool oa_buffer_check_unlocked(struct i915_perf_stream *stream)
* memory in the order they were written to.
* If not : (╯°□°）╯︵ ┻━┻
*/
- while (OA_TAKEN(tail, aged_tail) >= report_size) {
- void *report = stream->oa_buffer.vaddr + tail;
+ while (OA_TAKEN(iter, tail) >= report_size) {
+ void *report = stream->oa_buffer.vaddr + iter;
if (oa_report_id(stream, report) ||
oa_timestamp(stream, report))
break;
- tail = (tail - report_size) & (OA_BUFFER_SIZE - 1);
+ iter = (iter - report_size) & (OA_BUFFER_SIZE - 1);
}
- if (OA_TAKEN(hw_tail, tail) > report_size &&
+ if (OA_TAKEN(hw_tail, iter) > report_size &&
__ratelimit(&stream->perf->tail_pointer_race))
drm_notice(&stream->uncore->i915->drm,
"unlanded report(s) head=0x%x tail=0x%x hw_tail=0x%x\n",
head, tail, hw_tail);
- stream->oa_buffer.tail = gtt_offset + tail;
+ stream->oa_buffer.tail = gtt_offset + iter;
pollin = OA_TAKEN(stream->oa_buffer.tail - gtt_offset,
stream->oa_buffer.head - gtt_offset) >= report_size;
--
2.36.1
