x11-drivers/nvidia-drivers: warn about intel+nvidia laptops in 0/575

Some users may have already upgraded and missed the message but it
does not hurt to add one anyway.

Not heard of this from Gentoo users yet (the beta was unkeyworded),
but it seems(?) to be a widespread issue on other distros with 575.
Supposedly does not manifest with 570.x, and unclear if kernel 6.15.x
is related.

Thankfully, USE=kernel-open is off-by-default, 575.x is not a stable
candidate either way, and normal desktops seem fine, so it should not
affect *that* many users. Do not believe this issue requires masking
this version (lot of interesting fixes for other users).

Signed-off-by: Ionen Wolkens <ionen@gentoo.org>

x11-drivers/nvidia-drivers/nvidia-drivers-575.57.08.ebuild

@@ -598,4 +598,17 @@ pkg_postinst() {
 		elog "enables the use of the GSP firmware by default. *If* experience regressions,"
 		elog "please see '${EROOT}/etc/modprobe.d/nvidia.conf' to optionally disable."
 	fi
+
+	[[ ${PV} == 575.57.08 ]] || die "TODO: recheck intel+nvidia status & cleanup"
+	if use kernel-open && ver_replacing -lt 575; then
+		ewarn
+		ewarn "WARNING:"
+		ewarn
+		ewarn "*If* using a hybrid Intel+NVIDIA laptop, be warned that several users"
+		ewarn "have reported issues where the GSP firmware fails to initialize when"
+		ewarn "USE=kernel-open is enabled with ${PN}-575.x. If affected,"
+		ewarn "either try to disable the USE or stick to ${PN}-570.x for now."
+		ewarn "Note that blackwell cards (aka 50xx+) require USE=kernel-open, so"
+		ewarn "downgrading will be the only option there for now."
+	fi
 }