For me, at least TWRP is working, but same situation with normal boot, after screen replacement I am unable to boot to android, only lenovo screen keeps in cycle. Is there any chance to get this fixed?
I have found out, that compiling this kernel needs linaro 4.9 to work, and also use of compiler cache:
Now the question remains:
How to find out, which driver/option to enable in kernel order to make aftermarket touchscreen work?
Stock ROM is working correctly, so maybe find out loaded modules / configurations?
Stock kernel found (5.1) on lenovo pages: ht t p s:// download.lenovo.com/consumer/open_source_code/lenovo_vibe_p1m_osc_201509.tar.gz
Stock kernel for P1 (6.0): h t t p s:// download.lenovo.com/consumer/open_source_code/lenovo_p1a42_osc_201608.zip
Aftermarket screen IC says FT5446DQQ so I think it is not a driver problem as far kernel has configured FT5446 drivers by default..