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    SubjectRe: [PATCH 1/6] drm/v3d: Document cache flushing ABI.
    On Mon, 3 Dec 2018 at 17:22, Dave Emett <david.emett@broadcom.com> wrote:
    >
    > > + * The caches (L1T, slice, and L2T) will be flushed before the job
    > > + * executes. The TLB writes are guaranteed to have been flushed by
    >
    > I would say before *each* job executes, as the caches are flushed
    > before both bin and render.
    > I wouldn't say "the caches" as not all of the V3D caches are flushed
    > before executing a control list. In particular, the VCD cache is not
    > cleared by the kernel driver (not even sure if there is a register
    > interface to do this); it is expected that the control list will do
    > this itself (using the CLEAR_VCD_CACHE instruction).
    > On 3.3 and earlier there is a separate L2C for instructions/uniforms
    > and a GCA. These do need to be flushed, and it looks like they are, so
    > they should be mentioned here.

    Correction: on *3.2* and earlier there is a separate L2C for
    instructions/uniforms. On 3.3 and earlier there is a GCA.

    It looks like we're currently unconditionally writing the L2C clear
    registers. We should really only be doing this on 3.2 and earlier.

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