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    SubjectRe: [RFC PATCH 0/5] Add smp booting support for Qualcomm ARMv8 SoCs
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    On Apr 10, 2015, at 5:05 AM, Catalin Marinas <catalin.marinas@arm.com> wrote:

    > On Thu, Apr 09, 2015 at 12:37:06PM -0500, Kumar Gala wrote:
    >> This patch set adds support for SMP boot on the MSM8x16 family of Qualcomm SoCs.
    >>
    >> To support SMP on the MSM8x16 SoCs we need to add ARMv8/64-bit SCM interfaces to
    >> setup the boot/release addresses for the secondary CPUs. In addition we need
    >> a uniquie set of cpu ops. I'm aware the desired methods for booting secondary
    >> CPUs is either via spintable or PSCI. However, these SoCs are shipping with a
    >> firmware that does not support those methods.
    >
    > And the reason is? Some guesses:
    >
    > a) QC doesn't think boot interface (and cpuidle) standardisation is
    > worth the effort (to put it nicely)
    > b) The hardware was available before we even mentioned PSCI
    > c) PSCI is not suitable for the QC's SCM interface
    > d) Any combination of the above
    >
    > I strongly suspect it's point (a). Should we expect future QC hardware
    > to do the same?
    >
    > You could argue the reason was (b), though we've been discussing PSCI
    > for at least two years and, according to QC press releases, MSM8916
    > started sampling in 2014.
    >
    > The only valid reason is (c) and if that's the case, I would expect a
    > proposal for a new firmware interface protocol (it could be PSCI-based),
    > well documented, that can be shared with others that may encounter the
    > same shortcomings.
    >
    > --
    > Catalin

    Does it matter? I’ve always felt the kernel was a place of inclusion. Qualcomm choose for whatever reason to not use PSCI or spin table. You don’t like it, I might not like it, but it is what it is.

    - k

    --
    Qualcomm Innovation Center, Inc.
    The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
    a Linux Foundation Collaborative Project



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