From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH v2 4/4] media: staging: tegra-vde: Power-cycle hardware on probe Date: Fri, 26 Jun 2020 09:48:18 +0200 Message-ID: <20200626074818.GD3109062@ulmo> References: <20200624150847.22672-1-digetx@gmail.com> <20200624150847.22672-5-digetx@gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="VMt1DrMGOVs3KQwf" Return-path: Content-Disposition: inline In-Reply-To: <20200624150847.22672-5-digetx@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Osipenko Cc: Jonathan Hunter , Mauro Carvalho Chehab , Hans Verkuil , linux-media@vger.kernel.org, linux-tegra@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org --VMt1DrMGOVs3KQwf Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jun 24, 2020 at 06:08:47PM +0300, Dmitry Osipenko wrote: > VDE partition is left turned ON after bootloader on most devices, hence > let's ensure that it's turned OFF in order to lower power leakage while > hardware is idling by turning it ON and OFF during of the driver's probe. >=20 > Signed-off-by: Dmitry Osipenko > --- > drivers/staging/media/tegra-vde/vde.c | 8 ++++++++ > 1 file changed, 8 insertions(+) >=20 > diff --git a/drivers/staging/media/tegra-vde/vde.c b/drivers/staging/medi= a/tegra-vde/vde.c > index b64e35b86fb4..3be96c36bf43 100644 > --- a/drivers/staging/media/tegra-vde/vde.c > +++ b/drivers/staging/media/tegra-vde/vde.c > @@ -1068,6 +1068,14 @@ static int tegra_vde_probe(struct platform_device = *pdev) > pm_runtime_use_autosuspend(dev); > pm_runtime_set_autosuspend_delay(dev, 300); > =20 > + /* > + * VDE partition may be left ON after bootloader, hence let's > + * power-cycle it in order to put hardware into a predictable lower > + * power state. > + */ > + pm_runtime_get_sync(dev); > + pm_runtime_put(dev); > + > return 0; > =20 > err_deinit_iommu: Shouldn't this happen automatically? My understanding is that power domains are turned on automatically before ->probe() and then unless a runtime PM reference is taken during ->probe() it will get turned off again after ->probe()? Is that not happening? Is auto-suspend perhaps getting in the way somehow? Thierry --VMt1DrMGOVs3KQwf Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAl71qEIACgkQ3SOs138+ s6F2BRAAqITs8YO7f90qNTucc+6aVUaPhcOoeLRSA384Hh4M4RfzKwKV1ivLrL4H VkMWU+BB4N5ABiJxNbLnwuvh6O7y9vg1l7ovi/lg4qHTj96GmdZAuXpEFsqG2VWY WMUX60Wc3x6vqhJPVnroCRj++WmA74nlzieWnzrR36wF91p7lpisLNjlGY90VrOq nSatzzNO2Na9BEQnVzGqxYU7OThPB/MHJOviY5X21SXWCluc40tb0Qz4d8pbDUqB aXQ0uMNrf8kgX0YyARa+R+U8op8R9oRTkgRCf1SHwifbb2dlnjIw2sw27ORyfzr8 h87kcTOlkTZhxehUG7eIHpyIUmgCWpXtBwt+Blww0o28LxW0+yEQHymenMlUNtY6 18mSdMQGO2k6dwgWa2znsETezLrv1lYX2nT6FxZ6niTzYZRPiA2WJ4YTa79h5yDJ KtbvBz9b2kKzMl6R5084U2P8fh7tZH2oTs3W6n3f/NnA5+eGIBeCKu1wLQrh1M9u 2bTTPOrJOhAQMZiJCq6CJ4Bmr5+X7Cmp5bTkNOiY9lBweTpWcJHAWqgybEHCajEf 0dTnrWm4BVwGmfYUDNsm8rffkO/avUUvYBC21kZr2ATYWkrYQyheooiYC5qNLJFL lJClO+wrkJuTqWiyB0BdOJ90jHnFMolBZOjTN/Ot7BkPCgWo8uE= =0TFC -----END PGP SIGNATURE----- --VMt1DrMGOVs3KQwf--