espcomm_sync failed and espcomm_send_command(FLASH_DOWNLOAD_DATA) failed

[AshishCdev]

esptool-ck works fine for the x64 and x86 machine. Since I am using R-Pi for binary loading, It's ARM version doesn't seem to work reliably. This version shows unpredictable behaviour and termination of binary loading in the middle of the loading process. I tried with another tool esptool.py and it showed the same behaviour
Also sometimes ESP doesn't run after programming. Although the program gets loaded properly with 100 percent. Reprogramming again with toggling the baud rate resolves the issue sometimes.

I am programming many of them and this process needs to be fast. My power supply is sufficient to provide enough power. Please guide me if I am missing something or doing wrong.