Description

Some high-resolution monitors (QHD/4K) will not output the desktop, and will enter sleep mode, directly after booting up an Armbian 23.8.1 desktop image and completing the initial setup questions.

When such a monitor is attached, the kernel will auto-detect the SimpleDRM graphics driver, which is then prioritized over the Panfrost graphics driver. However, SimpleDRM outputs to a virtual output, while Panfrost outputs to the actual HDMI port. This causes the monitor to not receive any data.

By blacklisting the simpledrm kernel module, Panfrost will take care of accelerated graphics (for any monitor) by default. Advanced users can still access simpledrm if required.

Jira reference number [AR-1908]

How Has This Been Tested?

An Armbian image with a Cinnamon desktop has been build using the default options. That image has been written to a SD-card and tested on both a QHD monitor (that had the initial problem) and an older Full HD monitor (that worked fine before as well). In both test cases, the simpledrm kernel module was not loaded. The desktop was visible on the HDMI output both on initial boot and after subsequent reboots.

Checklist:

• [X] My code follows the style guidelines of this project
• [X] I have performed a self-review of my own code
• [X] I have commented my code, particularly in hard-to-understand areas
• [N/A] I have made corresponding changes to the documentation
• [X] My changes generate no new warnings
• [N/A] Any dependent changes have been merged and published in downstream modules

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