From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH] i2c: tegra: Restore pinmux on system resume Date: Thu, 23 Jan 2020 12:19:27 +0100 Message-ID: <20200123111927.GH1105@ninjato> References: <20191213134417.222720-1-thierry.reding@gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="4C6bbPZ6c/S1npyF" Return-path: Received: from sauhun.de ([88.99.104.3]:52288 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729240AbgAWLT3 (ORCPT ); Thu, 23 Jan 2020 06:19:29 -0500 Content-Disposition: inline In-Reply-To: <20191213134417.222720-1-thierry.reding@gmail.com> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: Thierry Reding Cc: Jon Hunter , Dmitry Osipenko , linux-i2c@vger.kernel.org, linux-tegra@vger.kernel.org --4C6bbPZ6c/S1npyF Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Dec 13, 2019 at 02:44:17PM +0100, Thierry Reding wrote: > From: Thierry Reding >=20 > Depending on the board design, the I2C controllers found on Tegra SoCs > may require pinmuxing in order to function. This is done as part of the > driver's runtime suspend/resume operations. However, the PM core does > not allow devices to go into runtime suspend during system sleep to > avoid potential races with the suspend/resume of their parents. >=20 > As a result of this, when Tegra SoCs resume from system suspend, their > I2C controllers may have lost the pinmux state in hardware, whereas the > pinctrl subsystem is not aware of this. To fix this, make sure that if > the I2C controller is not runtime suspended, the runtime suspend code is > still executed in order to disable the module clock (which we don't need > to be enabled during sleep) and set the pinmux to the idle state. >=20 > Conversely, make sure that the I2C controller is properly resumed when > waking up from sleep so that pinmux settings are properly restored. >=20 > This fixes a bug seen with DDC transactions to an HDMI monitor timing > out when resuming from system suspend. >=20 > Signed-off-by: Thierry Reding Do we still need this after I applied "[PATCH v5 0/8] NVIDIA Tegra I2C driver fixes and improvements" ? --4C6bbPZ6c/S1npyF Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAl4pgT4ACgkQFA3kzBSg KbYorg//bjTFQloGcIUrKE3jkos9WC0qW9VoPPS2vVkoEIrwXvIVy7IvNjzYaPTy ES56UjWsK4/FjZrcrluprZ4GdrwApmSKLzmfXHrY6Z4TTxBQQRg01G6eN4iNMasP PX/sbometIjhCYepFZytajnqQxa7MP8MsCitE/dwTkEEE66DbsXmvOeuNSywtuvV M/nmgDGd3Lbg7RgjoJjQNs0QmFF0eIOeA18o1K9k46n8mzlEl0QaOf5D9k5NnnHL RSw0Hxek6ZQKf8/g29JUgB5uNmUg7lPz0F1/xpgXmXTRO53Murq/QAmWJmoy9nwf bkCSdIAQjZMEI69B984Mz8t84NnYTLLFDLFU+Xw6CrAqVp07jjy2vu+iQLO6zjXj 73AX40xGJcMps61Zp1oN5R0suS9Ly2DbBH99WKZOi4oVKQXdivl5qROrODn/rgpS AZy6khg6TmWeSJuWN9PEdUqbRRld/WoX1N6SzydG4b2PXyFHauEfdEa2XLcGSuTj yhIbH4KBfLtBU6gyincrK/xsZJqzLSsY2NNfWzVDVhZLpgKqM9DRb599BPc4rGpO KApFZs1aIs25VHsrTdgCFgyg9mTvqMTUABIBJQiU+HXeVNGRsNU3vHTXvNtwNFLT 8XzZd7Bs0lfdZY3TMm8Sg9j3t6E3JbtClgINmGHePt71lKXXGLE= =AblB -----END PGP SIGNATURE----- --4C6bbPZ6c/S1npyF--