Not for Linux they're not. IIRC Audio and camera don't work, and firmware is non-redistributable and so you need to mooch it off a Windows partition. On top of that the performance on Linux hasn't been great either.
That's true Qualcomm in general, but is fortunately outdated for the Snapdragon Elite X (and only the X). Qualcomm has been upstreaming patches to Linus' tree[1] - but only for the Elite X - the Elite P processors get the classic Qualcomm treatment.
You're mangling Qualcomm's branding to the point that it's impossible to be sure what you're trying to say. Qualcomm's current laptop SoCs are called "Snapdragon X Elite" or "Snapdragon X Plus" or "Snapdragon X", all derived from various bins of two SoC designs, and all pretty much in the same boat for driver support purposes. "Snapdragon X2 Elite" and lesser siblings are due in the first half of next year, so a respectable degree of Linux support would mean having driver support for those chips in an upstream kernel release now so that there might be a mainstream distro supporting the hardware at some point in the quarter after the hardware ships.
My apologies to you and the entire Qualcomm marketing team for my brand-guideline violations - I was going off the top of my head. What I meant in my inscrutable comment was: "Elite X" => "X Elite", "Elite P" => "X Plus", I really should not have mangled the products using such an elegant and intuitive naming convention.
Ok, so having clarified the naming, it still looks like you're wrong about which chips are getting driver support upstreamed, because the Snapdragon X Plus parts are (with maybe one exception, IIRC) literally the same chip as the Snapdragon X Elite parts. Do you really believe that the upstream Linux kernel would accept patches that are specifically crafted to only work on certain bins of the chip, or to fail to enable a peripheral if not enough of the CPU cores are enabled?
Don't take my word for it - go to the Ubuntu Concept Snapdragon thread[1] and search for "plus" or "x1p".
> Do you really believe that the upstream Linux kernel would accept patches that are specifically crafted to only work on certain bins of the chip, or to fail to enable a peripheral if not enough of the CPU cores are enabled?
It takes more than a kernel patch to boot a laptop. Qualcomm has been neglecting to release the dtbs for Plus laptops. If you want good peripheral support, don't buy a "plus" variant. Getting back to your question, the answer is "Yes, Linux has always accepted patches that only work on some configurations" with no requirement to support all h/w configuration variants. Infact, some configurations are so obscure only the submitter can test - the maintainer/subsystem chief/Linus may not even know what the potential variants are.