lkml.org 
[lkml]   [2007]   [Aug]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: 2.6.22 regression: thermal trip points
    On Thu, Aug 02, 2007 at 01:45:00PM +0200, Thomas Renninger wrote:
    > On Thu, 2007-08-02 at 12:13 +0100, Matthew Garrett wrote:
    > > I strongly suspect that the vast majority[1] of hardware that "needs"
    > > the trip points changing works perfectly well under Windows, so it's
    > > likely to be papering over bugs in the kernel. It'd be nice if we fixed
    > > those rather than encouraging people to poke stuff into /proc,
    > Some arguments against that:
    > - You cannot tell a customer: Wait for the kernel in half a year.
    > This is the time it at least needs until a laptop got sold, the
    > problem is found, a patch is written and checked in and finally
    > hits the distribution.

    We have to do so frequently. New hardware often exposes bugs in the
    kernel.

    > - You can also not backport fixes as ACPI patches mostly have the
    > potential to break other machines/BIOSes
    > - There also exist the policy to not fix up/workaround totally broken
    > AML BIOS implementations

    The policy has been to attempt to be bug-compatible with Windows
    whenever possible for some time now.

    > - We do not need to and never will be able to copy or do the same
    > Windows is doing

    Given that many vendors still only test against Windows, that's exactly
    what we need to do.

    > > especially when doing so is guaranteed to break in really confusing ways
    > > with a lot of hardware. The firmware can reset the trip points at
    > > essentially arbitrary times and is well within its rights to expect the
    > > OS to actually pay attention to them.
    > What the hell is so wrong with:
    >
    > Let the user override the trip points. If he does so, ignore
    > thermal trip point updates from BIOS. Don't care for hysteresis
    > BIOS implementations (these are the BIOS trip point updates).

    No, that's not the only reason for notifications. Alteration in hardware
    state may also force a recalculation of trip point (adding a battery to
    a bay rather than a DVD drive may require the platform to be kept at a
    lower temperature)

    > If user changes them, it's his fault, he doesn't need to...
    > Make sure that trip points can only be lowered, compared to the
    > initially fetched one from BIOS.

    Surely people want this functionality so that they can raise trip
    points?

    --
    Matthew Garrett | mjg59@srcf.ucam.org
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/
    \
     
     \ /
      Last update: 2007-08-02 13:59    [from the cache]
    ©2003-2014 Jasper Spaans. hosted at Digital Ocean