The IMX serial driver is broken in the 4.9.x tree since 4.9.89. Uwe's patch6df765dca378bddf994cfd2044acafa501bd800f please apply to clear the situation. I know you very busy! -It's best to email sta...@vger.kernel.org for stuff like this, as I almost missed it... Now queued up. greg k-h
Thanks! will follow up and cc the stable@ next time. Chris