• Rafael J. Wysocki's avatar
    ACPI / PNP: Avoid conflicting resource reservations · 0f1b414d
    Rafael J. Wysocki authored
    Commit b9a5e5e1 "ACPI / init: Fix the ordering of
    acpi_reserve_resources()" overlooked the fact that the memory
    and/or I/O regions reserved by acpi_reserve_resources() may
    conflict with those reserved by the PNP "system" driver.
    
    If that conflict actually takes place, it causes the reservations
    made by the "system" driver to fail while before commit b9a5e5e1
    all reservations made by it and by acpi_reserve_resources() would be
    successful.  In turn, that allows the resources that haven't been
    reserved by the "system" driver to be used by others (e.g. PCI) which
    sometimes leads to functional problems (up to and including boot
    failures).
    
    To fix that issue, introduce a common resource reservation routine,
    acpi_reserve_region(), to be used by both acpi_reserve_resources()
    and the "system" driver, that will track all resources reserved by
    it and avoid making conflicting requests.
    
    Link: https://bugzilla.kernel.org/show_bug.cgi?id=99831
    Link: http://marc.info/?t=143389402600001&r=1&w=2
    Fixes: b9a5e5e1 "ACPI / init: Fix the ordering of acpi_reserve_resources()"
    Reported-by: default avatarRoland Dreier <roland@purestorage.com>
    Cc: All applicable <stable@vger.kernel.org>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    0f1b414d
acpi.h 24.8 KB