From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH] i2c: Re-instate body of i2c_parent_is_i2c_adapter() Date: Tue, 14 Jan 2014 17:12:54 +0100 Message-ID: <20140114161254.GA6442@katana> References: <1389648544-4201-1-git-send-email-swarren@wwwdotorg.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="opJtzjQTFsWo+cga" Return-path: Content-Disposition: inline In-Reply-To: <1389648544-4201-1-git-send-email-swarren@wwwdotorg.org> Sender: linux-kernel-owner@vger.kernel.org To: Stephen Warren Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Stephen Warren , Phil Carmody , stable@vger.kernel.org List-Id: linux-i2c@vger.kernel.org --opJtzjQTFsWo+cga Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jan 13, 2014 at 02:29:04PM -0700, Stephen Warren wrote: > From: Stephen Warren >=20 > The body of i2c_parent_is_i2c_adapter() is currently guarded by > CONFIG_I2C_MUX instead. This paragraph sounds strange to me. I'll update it a little. After that I'll go looking for a brown paper bag... > Among potentially other problems, this resulted in i2c_lock_adapter() > only locking I2C mux child adapters, and not the parent adapter. In > turn, this could allow inter-mingling of mux child selection and I2C > transactions, which could result in I2C transactions being directed to > the wrong I2C bus, and possibly even switching between busses in the > middle of a transaction. >=20 > One concrete issue caused by this bug was corrupted HDMI EDID reads > during boot on the NVIDIA Tegra Seaboard system, although this only > became apparent in recent linux-next, when the boot timing was changed > just enough to trigger the race condition. >=20 > Fixes: 3923172b3d70 ("i2c: reduce parent checking to a NOOP in non-I2C_MU= X case") > Cc: Phil Carmody > Cc: > Signed-off-by: Stephen Warren Applied to for-current, thanks for catching this one! --opJtzjQTFsWo+cga Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.15 (GNU/Linux) iQIcBAEBAgAGBQJS1WIGAAoJEBQN5MwUoCm2fgIP/jxjNkl/nRcy5JSZvcJ0DDLb eJl1ZXZXM12ZNLsJrhzo2Vwu5JoKhRaozJjdsSjMHfqa4w11i6QOT362hN22iHeD fphck/Gf5HoLwAlTtWNXwFq48TdyYz8eW13OsbonkVeYegLxvsX8k+l0i2hcOgcF L1zHIR0rLLyEt/ID7kafkSckv8jgd7KXgKmodHyr6UzcDBE7730ZexMMryLavTvo K2N+mTRYdCsU4/W76quiXck5cBsx/2zbRahEafZaQEKSdPFJvqontZ/L011TxgvH qowj7ejKUJS5sxeoEp38NWCIqSNJh7U+u4U8tCP6y7sij1fGLhO7bzT81TQR0Qwe nrZ3eoXZwA9Ej9F6ARk+p028WC9SdWUzI72grpIUWja2QFdePqlFTzTVvVl2dUAI QtxsIbfmX3CxhKx4CnYeyvanDMp4ga9faNioiyBQXCJCOKOS+hvS+G+LNnbuRU3A GryB0ZvmfLGuo6aXJfJr5MlZnszU3KO9Jw5Ae6AFipTpiIwR9nebcJxz+ea4ruUt oo+RNPf8v/h/imcAZcjMYSJNH2DlEjCaYsHR3gLF9yupXT7mpFZZraWbDnMyvGtO hgIyNJLD2Px7cp05Ak9JRyFf1tmiNrOeqSuvd9eXt4CSkDCEyyTDrdTk2v/is+Hd Y9pJokwq0a5/2kkebe4M =gq0B -----END PGP SIGNATURE----- --opJtzjQTFsWo+cga--