Re: [PATCH v2 6/6] memory: renesas-rpc-if: Use runtime PM autosuspend after transfers

"Lad, Prabhakar" <[email protected]> Mon, 3 Aug 2026 10:07:30 +0100
Newsgroups org.kernel.vger.linux-renesas-soc,org.kernel.vger.linux-kernel
Message-ID <CA+V-a8uurMAN5nv50GBN6O5jxLzA27c0vo6Af0EP45AqSWph7w@mail.gmail.com>
Hi Wolfram,

On Mon, Aug 3, 2026 at 8:33=E2=80=AFAM Wolfram Sang
<[email protected]> wrote:
>
> On Mon, Jul 27, 2026 at 11:34:49AM +0100, Prabhakar wrote:
> > From: Lad Prabhakar <[email protected]>
> >
> > Replace pm_runtime_put() with pm_runtime_put_autosuspend() after manual
> > transfers and direct memory-mapped read/write operations.
> >
> > Flash page programming may be performed as a sequence of closely spaced
> > transfer operations. Calling pm_runtime_put() after each operation allo=
ws
> > the runtime PM core to suspend the controller between successive
> > transfers, introducing unnecessary suspend/resume cycles and potentiall=
y
> > interrupting multi-step transfer sequences.
> >
> > Use pm_runtime_put_autosuspend() instead so the controller remains
> > active while transfers continue, allowing it to suspend only after an
> > idle period.
> >
> > Signed-off-by: Lad Prabhakar <[email protected]>
>
> I tested this series with my SparrowHawk but it doesn't use the xSPI
> code paths, so only this patch is only affected. No improvements, but
> neither regressions.
>
> Tested-by: Wolfram Sang <[email protected]>
>
Thank you for testing this.

> > Note corresponding pm_runtime_set_autosuspend_delay()/pm_runtime_use_au=
tosuspend()
> > calls are already present in SPI driver.
>
> Unless I am missing it, there is no pm_runtime_set_autosuspend_delay()
> in the driver nor in this patchset?
>
Its been added as part of the SPI driver which is in -next [0].

[0] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/com=
mit/?h=3Dnext-20260731&id=3Daf4b98e33d5607f80b49e792e0a74cb068d810f0

Cheers,
Prabhakar