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    SubjectRe: [PATCH tip:irq/core v1] genirq: remove auto-set of the mask when setting the hint
    On Fri, May 21, 2021 at 7:56 AM Thomas Gleixner <tglx@linutronix.de> wrote:
    >
    > Nitesh,
    >
    > On Thu, May 20 2021 at 20:03, Nitesh Lal wrote:
    > > On Thu, May 20, 2021 at 5:57 PM Nitesh Lal <nilal@redhat.com> wrote:
    > >> I think here to ensure that we are not breaking any of the drivers we have
    > >> to first analyze all the existing drivers and understand how they are using
    > >> this API.
    > >> AFAIK there are three possible scenarios:
    > >>
    > >> - A driver use this API to spread the IRQs
    > >> + For this case we should be safe considering the spreading is naturally
    > >> done from the IRQ subsystem itself.
    > >
    > > Forgot to mention another thing in the above case is to determine whether
    > > it is true for all architectures or not as Thomas mentioned.
    >
    > Yes.
    >
    > >>
    > >> - A driver use this API to actually set the hint
    > >> + These drivers should have no functional impact because of this revert
    >
    > Correct.
    >
    >
    > >> - Driver use this API to force a certain affinity mask
    > >> + In this case we have to replace the API with the irq_force_affinity()
    >
    > irq_set_affinity() or irq_set_affinity_and_hint()

    Ah yes! my bad. _force_ doesn't check the mask against the online CPUs.
    Hmm, I didn't realize that you also added irq_set_affinity_and_hint()
    in your last patchset.

    >
    > >> I can start looking into the individual drivers, however, testing them will
    > >> be a challenge.
    >
    > The only way to do that is to have the core infrastructure added and

    Right.

    > then send patches changing it in the way you think. The relevant
    > maintainers/developers should be able to tell you when your analysis
    > went south. :)

    Ack will start looking into this.


    --
    Thanks
    Nitesh

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