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    SubjectRe: [PATCH] pm_qos: Add QoS param, minimum system bus frequency
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    On Mon, 2010-01-04 at 13:38 -0800, mark gross wrote:
    > On Thu, Dec 31, 2009 at 05:20:27PM -0800, Daniel Walker wrote:
    > > From: Praveen Chidambaram <pchidamb@quicinc.com>
    > >
    > > In some systems, the system bus speed can be varied, usually
    > > based on the current CPU frequency. However, various device
    > > drivers and/or applications may need a faster system bus for I/O
    > > even though the CPU itself may be idle
    >
    > What happened to the discussion around multiple platforms needing
    > multiple bus pm_qos_requirements?
    >
    > Is system bus freq too generic? (I'm worried about the name space)
    > Is this ok? (I'm asking linux-pm for input here.)
    > On X86 would this be analogous to FSB, Memory, or PCI bus frequencies?
    > What will happen when there are two buses each wanting a PM_QOS
    > parameter? Is that a likely scenario?

    We can always change the naming in the future, but someone could add a
    PM_QOS_MEMORY_BUS_FREQ or PM_QOS_PERIPHERAL_BUS_FREQ in addition to this
    one.. Since it's all generic code having generic naming seems fine..

    > Also, on your platform you have a throttling driver controlling the
    > frequency of some bus, that will use this value as a constraint on how
    > far it will throttle. no? I would be interested in seeing this driver
    > sometime. (I just want to make sure no one bastardizes pm_qos into an
    > operating point thing. I'm not sure I can justify why but I want to
    > avoid that.)

    When you say "operating point thing" do you mean you don't want the
    frequency adjusted at runtime? You want it set once then move on?

    Daniel



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