This is the default value for the i915.force_probe module
parameter. Using the module parameter overrides this option.

Force probe the i915 driver for Intel graphics devices that are
recognized but not properly supported by this kernel version. Force
probing an unsupported device taints the kernel. It is recommended to
upgrade to a kernel version with proper support as soon as it is
available.

It can also be used to block the probe of recognized and fully
supported devices.

Use "" to disable force probe. If in doubt, use this.

Use "<pci-id>[,<pci-id>,...]" to force probe the i915 for listed
devices. For example, "4500" or "4500,4571".

Use "*" to force probe the driver for all known devices. Not
recommended.

Use "!" right before the ID to block the probe of the device. For
example, "4500,!4571" forces the probe of 4500 and blocks the probe of
4571.

Use "!*" to block the probe of the driver for all known devices.