diff --git a/internal/lsp/cache/parse.go b/internal/lsp/cache/parse.go
index 668c437f5c..ab55743ccf 100644
--- a/internal/lsp/cache/parse.go
+++ b/internal/lsp/cache/parse.go
@@ -278,7 +278,7 @@ func parseGo(ctx context.Context, fset *token.FileSet, fh source.FileHandle, mod
 
 	tok := fset.File(file.Pos())
 	if tok == nil {
-		// file.Pos is the location of the package declaration. If there was
+		// file.Pos is the location of the package declaration (issue #53202). If there was
 		// none, we can't find the token.File that ParseFile created, and we
 		// have no choice but to recreate it.
 		tok = fset.AddFile(fh.URI().Filename(), -1, len(src))
diff --git a/internal/lsp/debug/trace.go b/internal/lsp/debug/trace.go
index ca612867a5..bb402cfaa8 100644
--- a/internal/lsp/debug/trace.go
+++ b/internal/lsp/debug/trace.go
@@ -119,8 +119,6 @@ func formatEvent(ctx context.Context, ev core.Event, lm label.Map) string {
 }
 
 func (t *traces) ProcessEvent(ctx context.Context, ev core.Event, lm label.Map) context.Context {
-	t.mu.Lock()
-	defer t.mu.Unlock()
 	span := export.GetSpan(ctx)
 	if span == nil {
 		return ctx
@@ -128,11 +126,8 @@ func (t *traces) ProcessEvent(ctx context.Context, ev core.Event, lm label.Map)
 
 	switch {
 	case event.IsStart(ev):
-		if t.sets == nil {
-			t.sets = make(map[string]*traceSet)
-			t.unfinished = make(map[export.SpanContext]*traceData)
-		}
-		// just starting, add it to the unfinished map
+		// Just starting: add it to the unfinished map.
+		// Allocate before the critical section.
 		td := &traceData{
 			TraceID:  span.ID.TraceID,
 			SpanID:   span.ID.SpanID,
@@ -141,6 +136,13 @@ func (t *traces) ProcessEvent(ctx context.Context, ev core.Event, lm label.Map)
 			Start:    span.Start().At(),
 			Tags:     renderLabels(span.Start()),
 		}
+
+		t.mu.Lock()
+		defer t.mu.Unlock()
+		if t.sets == nil {
+			t.sets = make(map[string]*traceSet)
+			t.unfinished = make(map[export.SpanContext]*traceData)
+		}
 		t.unfinished[span.ID] = td
 		// and wire up parents if we have them
 		if !span.ParentID.IsValid() {
@@ -155,7 +157,19 @@ func (t *traces) ProcessEvent(ctx context.Context, ev core.Event, lm label.Map)
 		parent.Children = append(parent.Children, td)
 
 	case event.IsEnd(ev):
-		// finishing, must be already in the map
+		// Finishing: must be already in the map.
+		// Allocate events before the critical section.
+		events := span.Events()
+		tdEvents := make([]traceEvent, len(events))
+		for i, event := range events {
+			tdEvents[i] = traceEvent{
+				Time: event.At(),
+				Tags: renderLabels(event),
+			}
+		}
+
+		t.mu.Lock()
+		defer t.mu.Unlock()
 		td, found := t.unfinished[span.ID]
 		if !found {
 			return ctx // if this happens we are in a bad place
@@ -164,14 +178,7 @@ func (t *traces) ProcessEvent(ctx context.Context, ev core.Event, lm label.Map)
 
 		td.Finish = span.Finish().At()
 		td.Duration = span.Finish().At().Sub(span.Start().At())
-		events := span.Events()
-		td.Events = make([]traceEvent, len(events))
-		for i, event := range events {
-			td.Events[i] = traceEvent{
-				Time: event.At(),
-				Tags: renderLabels(event),
-			}
-		}
+		td.Events = tdEvents
 
 		set, ok := t.sets[span.Name]
 		if !ok {