Re: [PATCH v2 2/5] arm64: dts: r8a7795: Add cpuidle support for CA53 cores

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Eugeniu Rosca <erosca@de.adit-jv.com>
Cc: Ulrich Hecht <uli+renesas@fpond.eu>,
	"horms@verge.net.au" <horms@verge.net.au>,
	"khiem.nguyen.xt@renesas.com" <khiem.nguyen.xt@renesas.com>,
	"dien.pham.ry@renesas.com" <dien.pham.ry@renesas.com>,
	"takeshi.kihara.df@renesas.com" <takeshi.kihara.df@renesas.com>,
	Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
	"linux-renesas-soc@vger.kernel.org" 
	<linux-renesas-soc@vger.kernel.org>,
	"Wischer, Timo (ADITG/ESM)" <twischer@de.adit-jv.com>,
	"Maik.Scholz@de.bosch.com" <Maik.Scholz@de.bosch.com>,
	"Dirk.Behme@de.bosch.com" <Dirk.Behme@de.bosch.com>,
	Eugeniu Rosca <roscaeugeniu@gmail.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Linux PM list <linux-pm@vger.kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v2 2/5] arm64: dts: r8a7795: Add cpuidle support for CA53 cores
Date: Mon, 29 Jul 2019 09:44:52 +0200	[thread overview]
Message-ID: <CAMuHMdXiOBxUDXLcL6R7jHF4DMoH=72yMkSiv-51aV7cw3my9Q@mail.gmail.com> (raw)
In-Reply-To: <20190726094724.GA14913@vmlxhi-102.adit-jv.com>

Hi Eugniu,

CC cpuidle people

On Fri, Jul 26, 2019 at 11:47 AM Eugeniu Rosca <erosca@de.adit-jv.com> wrote:
> On Fri, Jul 26, 2019 at 11:13:29AM +0200, Rosca, Eugeniu (ADITG/ESM1) wrote:
> [..]
> > The culprit BSP commits are:
> > https://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas-bsp.git/commit/?id=3c3b44c752c4ee
> > https://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas-bsp.git/commit/?id=902ff7caa32dc71c
> >
> > Further narrowing it down, it turns out the CA57 cpuidle support is
> > not responsible for generating the issue. It's all about the CA53 idle
> > enablement. The reference target is H3-ES2.0-Salvator-X (the problem
> > originally emerged on M3-based customer HW).
> [..]
>
> Small amendment to the above (based on vanilla testing):
>
>  Version                              Issue reproduced?
>                                       (H3-ES2.0-Salvator-X)
>  v5.3-rc1-96-g6789f873ed37              No
>  v5.3-rc1-96-g6789f873ed37 + [1]        No
>  v5.3-rc1-96-g6789f873ed37 + [2]        No
>  v5.3-rc1-96-g6789f873ed37 + [1] + [2]  Yes
>
> [1] https://patchwork.kernel.org/patch/10769701/
> ("[v2,1/5] arm64: dts: r8a7795: Add cpuidle support for CA57 cores")
>
> [2] https://patchwork.kernel.org/patch/10769689/
> ("[v2,2/5] arm64: dts: r8a7795: Add cpuidle support for CA53 cores")

Thanks for your report and investigation!

Unfortunately your original report didn't make it to lore.kernel.org, and
probably also not to the list, due to the large audio attachment.

For the newly CCed people, the issue is about consistent dropouts during
audio playback using an in-house application, introduced by adding cpuidle
support to _both_ the big and LITTLE cores.

Thanks!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds