drm/xe/oa: Set stream->pollin in xe_oa_buffer_check_unlocked

We rely on stream->pollin to decide whether or not to block during
poll/read calls. However, currently there are blocking read code paths
which don't even set stream->pollin. The best place to consistently set
stream->pollin for all code paths is therefore to set it in
xe_oa_buffer_check_unlocked.

Fixes: e936f88 ("drm/xe/oa/uapi: Expose OA stream fd")
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250115222029.3002103-1-ashutosh.dixit@intel.com
(cherry picked from commit d3fedff)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Author: ashutoshx

drivers/gpu/drm/xe/xe_oa.c

@@ -237,7 +237,6 @@ static bool xe_oa_buffer_check_unlocked(struct xe_oa_stream *stream)
 	u32 tail, hw_tail, partial_report_size, available;
 	int report_size = stream->oa_buffer.format->size;
 	unsigned long flags;
-	bool pollin;
 
 	spin_lock_irqsave(&stream->oa_buffer.ptr_lock, flags);
 
@@ -282,22 +281,20 @@ static bool xe_oa_buffer_check_unlocked(struct xe_oa_stream *stream)
 	stream->oa_buffer.tail = tail;
 
 	available = xe_oa_circ_diff(stream, stream->oa_buffer.tail, stream->oa_buffer.head);
-	pollin = available >= stream->wait_num_reports * report_size;
+	stream->pollin = available >= stream->wait_num_reports * report_size;
 
 	spin_unlock_irqrestore(&stream->oa_buffer.ptr_lock, flags);
 
-	return pollin;
+	return stream->pollin;
 }
 
 static enum hrtimer_restart xe_oa_poll_check_timer_cb(struct hrtimer *hrtimer)
 {
 	struct xe_oa_stream *stream =
 		container_of(hrtimer, typeof(*stream), poll_check_timer);
 
-	if (xe_oa_buffer_check_unlocked(stream)) {
-		stream->pollin = true;
+	if (xe_oa_buffer_check_unlocked(stream))
 		wake_up(&stream->poll_wq);
-	}
 
 	hrtimer_forward_now(hrtimer, ns_to_ktime(stream->poll_period_ns));