As I read the MonitorDarkly code, it manipulates the monitor by writing
to DDC slave address x37, using operation code xC2. xC2 is apparently
is the GProbe operation code. (GProbe is the proprietary Genesis
protocol.) Operation code xC2 is not defined in the DDC spec, so it
would never be used by ddcutil or any other spec compliant DDC/CI
program. It's the use of operation code xC2, not normal reference to
manufacturer specific features with spec-defined operation codes, that's
the "trap door".
On 1/27/20 7:50 PM, Paul Wise wrote:
On Mon, Jan 27, 2020 at 4:50 PM Sanford Rockowitz wrote:
True. ddcutil internals were reworked some time ago for what I call User
Supplied Feature Definitions.
Another aspect of manufacturer-specific features is that they can be
used to do things that never should be allowed, like run arbitrary
code inside the monitor. I wonder if the Linux kernel should be
blocking access to at least the dangerous ones like Genesis' GProbe:
https://github.com/redballoonshenanigans/monitordarkly
