From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH v1] i2c: tegra: Remove suspend-resume Date: Wed, 30 May 2018 22:18:31 +0200 Message-ID: <20180530201831.6327alcmr2stgr3a@ninjato> References: <20180513211347.7187-1-digetx@gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="e5vf2g2grh6d4q2g" Return-path: Content-Disposition: inline In-Reply-To: <20180513211347.7187-1-digetx@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Osipenko Cc: Thierry Reding , Jonathan Hunter , Laxman Dewangan , linux-tegra@vger.kernel.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-i2c@vger.kernel.org --e5vf2g2grh6d4q2g Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, May 14, 2018 at 12:13:47AM +0300, Dmitry Osipenko wrote: > Nothing prevents I2C clients to access I2C while Tegra's driver is being > suspended, this results in -EBUSY error returned to the clients and that > may have unfortunate consequences. In particular this causes problems > for the TPS6586x MFD driver which emits hundreds of "failed to read > interrupt status" error messages on resume from suspend. This happens if > TPS6586X is used to wake system from suspend by the expired RTC alarm > timer because TPS6586X is an I2C device driver and its IRQ handler reads > the status register while Tegra's I2C driver is suspended, i.e. just after > kernel enabled IRQ's during of resume-from-suspend process. >=20 > Note that the removed tegra_i2c_resume() invoked tegra_i2c_init() which > performs HW reset. That seems was also not entirely correct because moving > tegra_i2c_resume to an earlier stage of resume-from-suspend process causes > I2C transfer to fail in the case of TPS6586X. It is fine to remove the > HW-reinitialization for now because it should be only needed in a case of > using lowest power-mode during suspend, which upstream kernel doesn't > support. >=20 > Signed-off-by: Dmitry Osipenko > Cc: Applied to for-next, thanks! --e5vf2g2grh6d4q2g Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAlsPBxcACgkQFA3kzBSg KbbFZw//SMNfWMlDFbsbF6Gb+7UXJQ9Yj8lterDd+32HwO2oAnM8VxIDdP9qkTTL ZsLy1/tddjX+6yX1H7MQw/fcOPk1FArnWXtAhCaE48SsaovY5Sgl1+X7RDDkzypt pUkneCDeVHmkVpaYq6X/4BLAodThAlES2QwMS/WWUBKpSdUHugYB0nHiD4Zb2tb0 x52sK1VU1r5C3sc3HMJK5HZ6n+k+qe0mw5bFpsmGXuxC1jf79sqdtfSRi/DMwl3t Do3rhhgDRrqYg/FTDR//w6cq7JNUTCnfS29LjtdWDA+opO2OLsjteOnhW53MFynw otvkVcf+RFeV7Jsgz4H7uCj0YAq7mGeqVqIfgDHfvtiFmDGqNdMsbSxN5xws5BNK Xjh+xHr64G5cZxtpJTUVVQItARUmETlhVU3jQtCbp7ioc1ehNw3GSWVyXiIqjG+g VSSaj32slpWhCckna7jH6cWLUosQRoKBe496Owdj1ugDAoH0714wmMcM6LZ8eZN8 3n1tzxsk6P4w4QLnJixcAfQVYqlj+kVghWX0sKZrVopshVYR6LpoTgcXJhutGD40 nTUuzuqabi/4SjmWndXlYKhRUTlGiORGsQO6yN2u7ae6HB5+sfLmHIbz/TgQqdrO CCbNtCDRv2eOaPfkd+uHL2TERcFuwMOz/IVvPEdeaPGjgr9KTxU= =Rq5I -----END PGP SIGNATURE----- --e5vf2g2grh6d4q2g--