From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH V2 01/11] soc/tegra: pmc: Initialise resets associated with a power partition Date: Thu, 30 Jun 2016 11:49:02 +0200 Message-ID: <20160630094902.GD1776@ulmo.ba.sec> References: <1467191877-26017-1-git-send-email-jonathanh@nvidia.com> <1467191877-26017-2-git-send-email-jonathanh@nvidia.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="BRE3mIcgqKzpedwo" Return-path: Content-Disposition: inline In-Reply-To: <1467191877-26017-2-git-send-email-jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jon Hunter Cc: David Airlie , Stephen Warren , Alexandre Courbot , Wolfram Sang , Rob Herring , Mark Rutland , Linus Walleij , dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-gpio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org --BRE3mIcgqKzpedwo Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jun 29, 2016 at 10:17:47AM +0100, Jon Hunter wrote: > When registering the Tegra power partitions with the generic PM domain > framework, the current state of the each partition is checked and used > as the default state for the partition. However, the state of each reset > associated with the partition is not initialised and so it is possible > that the state of the resets are not in the expected state. For example, > if a partition is on, then the resets should be de-asserted and if the > partition is off, the resets should be asserted. >=20 > There have been cases where the bootloader has powered on a partition > and only de-asserted some of the resets to some of the devices in the > partition. This can cause accesses to these devices to hang the system > when the kernel boots and attempts to probe these devices. >=20 > Ideally, the driver for the device should ensure the reset has been > de-asserted when probing, but the resets cannot be shared between the > PMC driver (that needs to de-assert/assert the reset when turning the > partition on or off) and another driver because we cannot ensure the > reset is in the correct state. >=20 > To ensure the resets are in the correct state, when using the generic > PM domain framework, put each reset associated with the partition in > the correct state (based upon the partition's current state) when > obtaining the resets for a partition. >=20 > Signed-off-by: Jon Hunter > --- > drivers/soc/tegra/pmc.c | 18 ++++++++++++++---- > 1 file changed, 14 insertions(+), 4 deletions(-) Applied to for-4.8/soc, thanks. Thierry --BRE3mIcgqKzpedwo Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAABCAAGBQJXdOsMAAoJEN0jrNd/PrOh3wsP/0CPXQ6h5zGWg6i6jCJXgFmV Ku/woQffcMkz8kgAFQ09rPjCscoP3t+xMI2TAPQECACvI7qv4w5GPDelTyuKOhW8 0OOl60CScXkd3mq1zUo8XpQkTjew1Ihyp3etgjYDuRFwFjwoeqlepLwlbXzmpMBM Ar70betKgtn2TRxsofW3+HDnwdXGxf6RZuuMi2t0bDpnZWVJIDJ8KokkFV2wdvFK vlk/D3SfWvzgzsvRoJ6NREi5d8ecpP+VWVODkNTOKsmLGEZBvS+fJeQTRibvMCCQ x13FCKkh4L1lQw5xca+qUR7E4vI84hLPlRg8kP+1z21PWdW9cqz0Y15i+U97CDBx D/b0uxd6775qSOqbY8W+qFHxKKY3AKEfQ3lThi/9ncIq1wlXXfWdb0h86XQ0wmDD viExSwFws2uychb5xoXkc/Ioi6/tqMpjR/ivsNsrKmWH47wLNxoXuNXxfPGuZweI uiBGX4Q+2txXCyppomGcukw1Zmwmj1HZUA1OYB94JtAbEWB7fAEhG4dOuZ9zS/xe PvAwCPKZdgU2qTfHrKTIzf9qiBFtv10jO3UtqGtgQyjE2iDWaVLFS7zq5UXsj2rl lRGtQ2EpV6Hi2CxhEI/ORBiwVT3A/seMKXU4jGKNGBdcLrqagVOBAIK3Lz7Vr/aZ ZZpU/EoP6+djCv/1BBaD =wt6P -----END PGP SIGNATURE----- --BRE3mIcgqKzpedwo--