Intel’s original DG1 discrete GPU was principally a development vehicle on the path to DG2/Alchemist. It did appear with the Iris Xe Max laptop dGPU in very few configurations but surprisingly it’s taken until now where the Intel Linux graphics driver is set to remove the experimental “force_probe” flag on these pre-Alchemist discrete GPUs.
Once DG2/Alchemist appeared, DG1 largely became an afterthought to the open-source Intel Linux graphics driver developers. It was a useful original development vehicle for working on discrete GPU support for the Intel i915 kernel driver and ANV/Iris Mesa drivers, but given the lack of any widespread adoption in the marketplace, it hasn’t been much of a focus since Alchemist arrived.
In going through that old code, Intel graphics driver engineer Ville Syrjala fixed up a few lingering problems to the DG1-specific code and finally is removing the “force_probe” requirement on that first generation Xe dGPU graphics. The “force_probe” module parameter is used during the early hardware bring-up phase by the Intel developers while the support is still treated as experimental to avoid the driver loading by default to avoid potential issues in that early hardware support.
Due to an oversight or simply losing DG1 interest since DG2, that DG1 force_probe requirement has been in place now for all these days. Ville commented in his patch series fixing up that DG1 support:
“Dunno why we still have .require_force_probe=1 on DG1 after all this time. I’m not aware of any real problems with DG1, so get rid of the force_probe requirement.
Generally the difficulty with DG1 is that it requires a 4GiB BAR for the local memory, and that’s not something that works on every system.”
Better late than never.
