Arch Linux

Horus

Member

Registered: 2021-10-02

Posts: 5

[SOLVED] "Input not supported" monitor message on boot.

Hello everyone,

I have just changed my gpu from an Nvidia GTX 1060 to a Radeon RX570. When I boot my PC (using GRUB), my monitor displays a floating message "Input not supported", and nothing is show: https://imgur.com/RCMNS1W. I have tried to go into the BIOS but I can't see anything there either. However, if I press 'enter', arch DOES boot , which tells me that GRUB IS there, it just for some reason can't print its output to the monitor. Furthermore, X is loading normaly. I have uninstalled all related nvidia packages I could find from my system. I have also installed all relevant amd packages, and verified that hardware acceleration is working for videos and for my browser.

Since the problem only shows up during boot (X is loading with no issue), I can only assume the problem is with GRUB itself. I have attempted to change its configuration according to the wiki, but there must be something I am missing:

# GRUB boot loader configuration

GRUB_DEFAULT=0
GRUB_TIMEOUT=-1
GRUB_DISTRIBUTOR="Arch"
GRUB_CMDLINE_LINUX_DEFAULT="loglevel=3 quiet splash intel_iommu=on iommu=pt radeon.pcie_gen2=0"
GRUB_CMDLINE_LINUX=""

# Preload both GPT and MBR modules so that they are not missed
GRUB_PRELOAD_MODULES="part_gpt part_msdos"

# Uncomment to enable booting from LUKS encrypted devices
#GRUB_ENABLE_CRYPTODISK=y

# Set to 'countdown' or 'hidden' to change timeout behavior,
# press ESC key to display menu.
GRUB_TIMEOUT_STYLE=menu

# Uncomment to use basic console
# GRUB_TERMINAL_INPUT=console

# Uncomment to disable graphical terminal
#GRUB_TERMINAL_OUTPUT=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=1920x1080x32
GRUB_GFXMODE=auto

# Uncomment to allow the kernel use the same resolution used by grub
GRUB_GFXPAYLOAD_LINUX=keep

# Uncomment if you want GRUB to pass to the Linux kernel the old parameter
# format "root=/dev/xxx" instead of "root=/dev/disk/by-uuid/xxx"
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
GRUB_DISABLE_RECOVERY=true

# Uncomment and set to the desired menu colors.  Used by normal and wallpaper
# modes only.  Entries specified as foreground/background.
#GRUB_COLOR_NORMAL="light-blue/black"
#GRUB_COLOR_HIGHLIGHT="light-cyan/blue"

# Uncomment one of them for the gfx desired, a image background or a gfxtheme
GRUB_BACKGROUND="/boot/grub/Chandelure.jpg"
#GRUB_THEME="/path/to/gfxtheme"

# Uncomment to get a beep at GRUB start
#GRUB_INIT_TUNE="480 440 1"

# Uncomment to make GRUB remember the last selection. This requires
# setting 'GRUB_DEFAULT=saved' above.
#GRUB_SAVEDEFAULT=true

# Uncomment to disable submenus in boot menu
#GRUB_DISABLE_SUBMENU=y

GRUB_DISABLE_OS_PROBER=false

I thought I might have to enable early KMS start, and have tried to have "MODULES=(amdgpu)" inside /etc/mkinitcpio.conf and did

mkinitcpio -P

afterwards, but that changed nothing.

The only thing I can still think of would be trying to reinstall grub, but I am not sure if that would change anything, and would rather avoid it, since I am dual booting with Windows and would have to go through the steps again to get it all to work.

UPDATE: I have discovered that the problem is with the monitor itself! Tested by simply changing the monitor. Furthermore, I have discovered that if I disable KMS by setting the nomodeset kernel paramenter, my monitor won't display anything. Even after logging in (before, it would show the console, even if x hadn't started). This still isn't a solution, since I would really like to use this monitor, and not the tiny old screen I am currently being forced to use. For reference, my monitor is an Acer SA270. I have also found this thread: https://forums.linuxmint.com/viewtopic.php?t=189186, which seems to suggest the problem is with the resolution on boot.
UPDATE2: I have now tried to force grub into a specific resolution/refresh rate with

GRUB_GFXMODE=1920x1080x75
GRUB_GFXPAYLOAD_LINUX=keep

but it still doesn't work.

Last edited by Horus (2021-10-09 00:50:32)

Horus

Member

Registered: 2021-10-02

Posts: 5

Re: [SOLVED] "Input not supported" monitor message on boot.

After a long struggle, I have finally fixed it. Essentially, it amounted to 2 things:

1 - Install the amd drivers on the windows side

2 - enable the option 'csm' in the BIOS

I do not know what csm does, but it did fix the thing for me. Now, since I couldn't see anything with my monitor in the BIOS, in order to change it I had to connect an old monitor to my computer instead of the one I am currently using. That allowed me to get into the BIOS and do the relevant changes. I would like to add that the grub menu still isn't at the correct resolution, however, at the very least I am able to see it (and I have normal access to the BIOS screen too).