To suppress only the specific spd5118 resume error lines (e.g., spd5118_resume [spd5118] returns -6 and failed to resume async: error -6) from appearing in dmesg output without silencing all spd5118-related messages, you can use kernel dynamic debugging (dyndbg) to filter these messages.

Here’s how to do it on Debian 13 (GNOME/HP laptop):

Step 1: Identify the Kernel Module

The messages are generated by the spd5118 kernel module. Confirm this by running:

lsmod | grep spd5118

If it’s loaded, proceed.

Step 2: Disable Specific Debug Messages

Use dyndbg to disable only the resume-related debug messages for spd5118. Run the following command as root:

echo 'module spd5118 +p; func spd5118_resume -p' | sudo tee /sys/kernel/debug/dynamic_debug/control

Explanation:

• module spd5118 +p: Enables all debug messages for the spd5118 module (default state).
• func spd5118_resume -p: Disables debug messages only for the spd5118_resume function, which is responsible for the lines you want to suppress.

Step 3: Verify the Changes

Check if the messages are suppressed by running:

sudo dmesg -w

Trigger the resume event (e.g., suspend/resume the laptop) and confirm the lines no longer appear.

Step 4: Make the Change Persistent

To ensure this persists across reboots, add the command to a startup script (e.g., /etc/rc.local or a systemd service).

Option 1: Using /etc/rc.local

1. Edit /etc/rc.local (create it if it doesn’t exist):
   bash

   Copy

   sudo nano /etc/rc.local

2. Add the following line before exit 0:
   bash

   Copy

   echo 'module spd5118 +p; func spd5118_resume -p' > /sys/kernel/debug/dynamic_debug/control

3. Make it executable:
   bash

   Copy

   sudo chmod +x /etc/rc.local

Option 2: Using a systemd Service

1. Create a service file:
   bash

   Copy

   sudo nano /etc/systemd/system/disable-spd5118-resume-messages.service

2. Add the following:
   ini

   Copy

   [Unit]
   Description=Disable spd5118 resume debug messages
   After=sysinit.target
   
   [Service]
   Type=oneshot
   ExecStart=/bin/sh -c 'echo "module spd5118 +p; func spd5118_resume -p" > /sys/kernel/debug/dynamic_debug/control'
   
   [Install]
   WantedBy=multi-user.target

3. Enable and start the service:
   bash

   Copy

   sudo systemctl enable disable-spd5118-resume-messages.service
   sudo systemctl start disable-spd5118-resume-messages.service

Alternative: Use dmesg Filtering (Temporary)

If you only want to hide these messages when running dmesg (without suppressing them at the kernel level), use:

sudo dmesg | grep -v "spd5118_resume\|failed to resume async"

This filters out the lines only for the current session.

Why This Works

• dyndbg allows granular control over kernel debug messages.
• Disabling spd5118_resume debug messages only suppresses the resume-related errors while preserving other spd5118 messages (e.g., initialization, other functions).

Reverting the Change

To re-enable all spd5118 debug messages:

echo 'module spd5118 +p' | sudo tee /sys/kernel/debug/dynamic_debug/control