[PATCH 4.12 170/196] drm/mst: Avoid processing partially received up/down message transactions

4.12-stable review patch. If anyone has any objections, please let me know. -- From: Imre Deak commit 636c4c3e762b62aa93632c645ca65879285b16e3 upstream. Currently we may process up/down message transactions containing uninitialized data. This can happen

[PATCH 4.12 170/196] drm/mst: Avoid processing partially received up/down message transactions

4.12-stable review patch. If anyone has any objections, please let me know. -- From: Imre Deak commit 636c4c3e762b62aa93632c645ca65879285b16e3 upstream. Currently we may process up/down message transactions containing uninitialized data. This can happen if there was an error