How to keep VGA output under Linux

There's VGA device for lots of server products , e.g. SKY-9240 , MIC-5345 ... etc.  Most of our testing environment is Linux based OS. Sometime user may face VGA was turned off (blank) after a certain period, with that we may get limited to check VGA pattern. 

Issue description (SKY-9240 IFD): 

We face VGA output nothing after 600 seconds on CentOS7-gid-efi-20181130_ver0_64_3.img.gz , and cannot check VGA pattern.

Root Cause:

It's from system settings. 

# cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-3.10.0-862.el7.x86_64 root=LABEL=C_m ro console=ttyS0,115200n8 console=tty0 crashkernel=512M biosdevname=0 net.ifnames=0 modprobe.blacklist=ipmi_ssif,qat_c62x,qat_dh895xcc,qat_c3xxx,intel_qat LANG=en_US.UTF-8 vga=0x318
#
# cat /sys/module/kernel/parameters/consoleblank
600

Solution:

Add parameter “consoleblank=0” at kernel boot in CentOS7-gid-efi-20181130_ver0_64_3.img.gz

# cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-3.10.0-862.el7.x86_64 root=LABEL=C_m ro console=ttyS0,115200n8 console=tty0 crashkernel=512M biosdevname=0 net.ifnames=0 modprobe.blacklist=ipmi_ssif,qat_c62x,qat_dh895xcc,qat_c3xxx,intel_qat LANG=en_US.UTF-8 vga=0x318 consoleblank=0
#
# cat /sys/module/kernel/parameters/consoleblank
0
# grubby --info /boot/vmlinuz-3.10.0-862.el7.x86_64
index=0
kernel=/boot/vmlinuz-3.10.0-862.el7.x86_64
args="ro console=ttyS0,115200n8 console=tty0 crashkernel=512M biosdevname=0 net.ifnames=0 modprobe.blacklist=ipmi_ssif,qat_c62x,qat_dh895xcc,qat_c3xxx,intel_qat LANG=en_US.UTF-8 consoleblank=0"
root=LABEL=C_m
initrd=/boot/initramfs-3.10.0-862.el7.x86_64.img
title=CentOS Linux (3.10.0-862.el7.x86_64) 7 (Core)