We are using a Nitrogen6q board, configured with 2GB of DDR3. I used the calibration excel sheet, run stress tool overnight, everythings ok, double checked DDR registers, timing, cs0 end, rows/columns, etc.
Kernel is 3.0.35 and Android is JB 4.2.2
Problem is as follow:
With 2GB enabled, both in u-boot and in board-mx6_nitrogen6x.c with the memblock_alloc_base(imx6_gpu_pdata.reserved_mem_size,SZ_4K, SZ_2G) call, in Android when we move the mouse pretty fast to slide screen left and right, sometimes the screen become black, system freeze, and the HW watchdog kick after 30 seconds. Some benchmarks quickly kill the board too. No logcat, nothing.
If we configure with 1GB, everything runs ok.
I discovered that some people have a somewhat related problem with 2GB (however we do not have trailing cursor problem)
On our board, if we disable hwcomposer_viv.imx6.so component, everything works ok with 2GB.
So it seems we have a related problem with 2GB, memory mapping, framebuffer base, GPU, something.
Anyone has a clue as to the change we have to do to make this works with 2GB of ram?