chapter 13 assets held for sale lecture

Hi, quick one on the online lecture. Impairment of 300 is posted against PL but there is revaluation surplus balance available of 1500 should it be charged against OCI then effectively lowering its balance to 1200? It there is one more impairment after its classified as held for sale will it be charged against OCI of there is balance or always against PL?
As always – Appreciate your help – Thanks!