From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Kemnade Subject: Re: [PATCH] omap3: give off mode enable a more prominent place Date: Mon, 4 Feb 2019 19:33:11 +0100 Message-ID: <20190204193311.102a60e6@kemnade.info> References: <20190202055827.12956-1-andreas@kemnade.info> <20190204155604.GH5720@atomide.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; boundary="Sig_/cZTCPF4_0JCD8_K5dVyf4=+"; protocol="application/pgp-signature" Return-path: In-Reply-To: <20190204155604.GH5720@atomide.com> Sender: linux-kernel-owner@vger.kernel.org To: Tony Lindgren Cc: linux@armlinux.org.uk, khilman@kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, letux-kernel@openphoenux.org List-Id: linux-omap@vger.kernel.org --Sig_/cZTCPF4_0JCD8_K5dVyf4=+ Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Mon, 4 Feb 2019 07:56:04 -0800 Tony Lindgren wrote: > * Andreas Kemnade [190202 06:01]: > > Enabling off mode was only reachable deeply hidden > > in the debugfs. As powersaving is an important feature, > > move the option out of its shady place. =20 >=20 > How about let's enable always if we have the twl4030 > configured to allow it? You can just check if the dts has > "ti,twl4030-power-idle" or "ti,twl4030-power-idle-osc-off" > properties set. >=20 > In order to enable deeper idle states, the user space still > needs to idle the UARTs and possibly other hardware blocking > idle. So we should be safe there. >=20 Let us not mix up runtime pm and system pm. The uarts need to be idled for runtime suspend, but they are off/ret for system suspend without userspace intervention, so allowing off mode will have an influence even without uart runtime suspend, and also probably for other powerdomains (non-core/per). So we still need to be sure to handle at least some erratas and context save/restore correctly. Your Idea seems to be in pseudocode if (powersaving_wanted) enable_off_mode() I had something in mind like if (system_is_trusted_to_handle_offmode() enable_off_mode() Regards, Andreas --Sig_/cZTCPF4_0JCD8_K5dVyf4=+ Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEPIWxmAFyOaBcwCpFl4jFM1s/ye8FAlxYhWcACgkQl4jFM1s/ ye+kpxAAtyNv7KqReXE73tqndnZZKlspBriMnP2PreLqcpI8myQPpBCb+aCtP+AS q1HAXiiMZVF41tdQ8cDXpEQPi537pGz7bmLxh+QLdAMrh6gVweUtBPX3dLIdn8+B lC+3awFj4B9d4jNCveHh8OeAb7mDYZN9XZDzSBaJztcXGNsY9P4sr57Ird4NzoFc A2zGUSofbgVKN2JPZT7FaSnv8sgd4khFwAV5FbIVK1R5gFWyj8ZCsnpdVSHYQIEd yUM9qTtYshGLs/0W19h6SFxlLk+2qCiLKdslXUytkpdcHZ/0zL6rJtHSIhlua+Gc UH6DoPhRO5Qo9Y63fy60lyRFm5cMeAosghDfzhvEBt58doLJVPwi06coRY/Tdmxn gK8/YSMTt+S1Sj3FvDODxsOACg1MxzdBwcG/sGQDBzV/8iyiiyA28WWcHFcNiQJ7 wzPPk8FMHRP2oipVIj7gQVz2Q+HvD+stuJhS8SPIiNKmNeZSdF0qh1s7kCrOfK+6 RQUNl2goH2+8ldkWhCdcswfGQyhpr00cdhxoxrKSaat/roLpbyTalGx/cm9lgoPH UkXzWKVTaqdjrN7/VxWjzamgjy4VMnq99BuF91UaOz0a63KPO6ob6cW+jVdtJ/I9 m/TeKon7/F+zxpuDxk5QWyZlA7YTFhzhCCMGXybBl9nX7m+bovA= =sAHi -----END PGP SIGNATURE----- --Sig_/cZTCPF4_0JCD8_K5dVyf4=+--