git: isa: allow the ISA PnP isolation scan to be skipped

[Antonio Huete Jimenez]

commit 956f1aa6bf782d2aa0c64161632a469b4f980a19
Author: Antonio Huete Jimenez <tuxillo at quantumachine.net>
Date:   Sun Jul 5 02:04:05 2026 +0200

    isa: allow the ISA PnP isolation scan to be skipped
    
    The scan probes several read-data ports, each running the full
    isolation protocol with mandatory DELAY()s; with no PnP cards present
    it finds nothing yet costs several seconds of boot time.  Add a
    hw.isa.pnp_disabled tunable (default 0) so systems known to have no
    ISA PnP hardware - virtual machines in particular - can skip it.
    
    NetBSD skips its isapnp probe automatically when SMBIOS slot tables
    report no ISA slots, but that data is absent on typical VMs (and
    NetBSD/OpenBSD do not compile ISA PnP into amd64 kernels at all), so
    an explicit tunable serves the VM case better.

Summary of changes:
 stand/boot/common/loader.8     |  5 +++++
 stand/boot/dloader/loader.conf |  1 +
 sys/bus/isa/pnp.c              | 12 ++++++++++++
 3 files changed, 18 insertions(+)

http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/956f1aa6bf782d2aa0c64161632a469b4f980a19


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