Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Tue, 19 Jan 2021 15:04:15 +0100
From:   Thierry Reding <thierry.reding@gmail.com>
To:     JC Kuo <jckuo@nvidia.com>
Cc:     gregkh@linuxfoundation.org, robh@kernel.org, jonathanh@nvidia.com,
        kishon@ti.com, linux-tegra@vger.kernel.org,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, nkristam@nvidia.com
Subject: Re: [PATCH v6 15/15] xhci: tegra: Enable ELPG for runtime/system PM
Message-ID: <YAbm39gww7F3okLP@ulmo>
References: <20210119085546.725005-1-jckuo@nvidia.com>
 <20210119085546.725005-16-jckuo@nvidia.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha256;
        protocol="application/pgp-signature"; boundary="m4cIgoQOaH3JJzUk"
Content-Disposition: inline
In-Reply-To: <20210119085546.725005-16-jckuo@nvidia.com>
User-Agent: Mutt/2.0.4 (26f41dd1) (2020-12-30)
Precedence: bulk


--m4cIgoQOaH3JJzUk
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Tue, Jan 19, 2021 at 04:55:46PM +0800, JC Kuo wrote:
> This commit implements the complete programming sequence for ELPG
> entry and exit.
>=20
>  1. At ELPG entry, invokes tegra_xusb_padctl_enable_phy_sleepwalk()
>     and tegra_xusb_padctl_enable_phy_wake() to configure XUSB PADCTL
>     sleepwalk and wake detection circuits to maintain USB lines level
>     and respond to wake events (wake-on-connect, wake-on-disconnect,
>     device-initiated-wake).
>=20
>  2. At ELPG exit, invokes tegra_xusb_padctl_disable_phy_sleepwalk()
>     and tegra_xusb_padctl_disable_phy_wake() to disarm sleepwalk and
>     wake detection circuits.
>=20
> At runtime suspend, XUSB host controller can enter ELPG to reduce
> power consumption. When XUSB PADCTL wake detection circuit detects
> a wake event, an interrupt will be raised. xhci-tegra driver then
> will invoke pm_runtime_resume() for xhci-tegra.
>=20
> Runtime resume could also be triggered by protocol drivers, this is
> the host-initiated-wake event. At runtime resume, xhci-tegra driver
> brings XUSB host controller out of ELPG to handle the wake events.
>=20
> The same ELPG enter/exit procedure will be performed for system
> suspend/resume path so USB devices can remain connected across SC7.
>=20
> Signed-off-by: JC Kuo <jckuo@nvidia.com>
> ---
> v6:
>    fix compiling warning: extra tokens at end of #ifdef directive
> v5:
>    avoid using xhci_get_rhub()
>    protect ELPG routines with (CONFIG_PM || CONFIG_PM_SLEEP)
> v4:
>    reshuffle the code to avoid these pre-declarations
> v3:
>    use 'unsigned int' for PHY index
>    remove unnecessary 'else'
>    drop IRQF_TRIGGER_HIGH when invokes devm_request_threaded_irq()
>=20
>  drivers/usb/host/xhci-tegra.c | 407 ++++++++++++++++++++++++++++++----
>  1 file changed, 370 insertions(+), 37 deletions(-)

Acked-by: Thierry Reding <treding@nvidia.com>

--m4cIgoQOaH3JJzUk
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
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=B9a4
-----END PGP SIGNATURE-----

--m4cIgoQOaH3JJzUk--