From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934004AbcCNJSc (ORCPT ); Mon, 14 Mar 2016 05:18:32 -0400 Received: from mail-wm0-f50.google.com ([74.125.82.50]:36074 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932438AbcCNJSX (ORCPT ); Mon, 14 Mar 2016 05:18:23 -0400 Date: Mon, 14 Mar 2016 10:18:19 +0100 From: Thierry Reding To: Sudip Mukherjee Cc: Wolfram Sang , linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, gregkh@linuxfoundation.org Subject: Re: [PATCH] i2c: i2c-core: do not use bus internal data Message-ID: <20160314091819.GA27975@ulmo> References: <1457351357-13457-1-git-send-email-sudipm.mukherjee@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="vkogqOf2sHV7VnPd" Content-Disposition: inline In-Reply-To: <1457351357-13457-1-git-send-email-sudipm.mukherjee@gmail.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --vkogqOf2sHV7VnPd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 07, 2016 at 05:19:17PM +0530, Sudip Mukherjee wrote: > The variable p is a data structure which is used by the driver core > internally and it is not expected that busses will be directly accessing > these driver core internal only data. >=20 > Signed-off-by: Sudip Mukherjee > --- >=20 > Reference of Greg's comment about it at: > https://lkml.org/lkml/2016/3/5/171 >=20 > drivers/i2c/i2c-core.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) >=20 > diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c > index 2949ab3..2f31fb5 100644 > --- a/drivers/i2c/i2c-core.c > +++ b/drivers/i2c/i2c-core.c > @@ -73,6 +73,7 @@ static struct device_type i2c_client_type; > static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *dr= iver); > =20 > static struct static_key i2c_trace_msg =3D STATIC_KEY_INIT_FALSE; > +static bool is_registered; > =20 > void i2c_transfer_trace_reg(void) > { > @@ -1529,7 +1530,7 @@ static int i2c_register_adapter(struct i2c_adapter = *adap) > int res =3D 0; > =20 > /* Can't register until after driver model init */ > - if (unlikely(WARN_ON(!i2c_bus_type.p))) { > + if (unlikely(WARN_ON(!is_registered))) { > res =3D -EAGAIN; > goto out_list; > } > @@ -1926,7 +1927,7 @@ int i2c_register_driver(struct module *owner, struc= t i2c_driver *driver) > int res; > =20 > /* Can't register until after driver model init */ > - if (unlikely(WARN_ON(!i2c_bus_type.p))) > + if (unlikely(WARN_ON(!is_registered))) > return -EAGAIN; > =20 > /* add the driver to the list of i2c drivers in the driver core */ > @@ -2118,6 +2119,7 @@ static int __init i2c_init(void) > if (IS_ENABLED(CONFIG_OF_DYNAMIC)) > WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); > =20 > + is_registered =3D true; > return 0; > =20 > class_err: This doesn't work. I see a number of these WARN_ON()s trigger and I think the reason is that i2c_init() always fails now. The cause seems to be that i2c_init() calls i2c_add_driver(&dummy_driver), which will now always fail, because is_register is set to true *after* that call. There is no way I see I2C working at all after this patch. Thierry --vkogqOf2sHV7VnPd Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAABCAAGBQJW5oHXAAoJEN0jrNd/PrOhz+EP/i0MmjqzAwYApIdyAwhABkUj jETLGqUHEZdbGlKcwtfb52TUqtwFvAmYw1Qz7hyqO4LPBZ2NNBBXhGlHWN8BVkZa JwOjopH4IosGlc3q0ck5pGKdQFB+dKbmlHR+r84doKe4utc558t89CYkE6ytsFrZ WcG89ngba4OxpQ41XTZW1o0cVXsUaNopqSnSB4OvPJVB3Z19EawkTeCC6u7ZBu0l n9efRJ8hRfWypZB0SdPLTiGm/JLQLovZTGNrJ50QG7Wn/6mlhl2l8X/fhD9p7tz0 FyvccRU05AgE07L4zA0w9/izGV19SpxsdYBsVPfyMVwuR81aR8yZRKR64hZFiWZp UOblqLNgkohtLOXjYBY0O1UtQlXSBd3GURM/AhtwM/g06AlHb9sGGQm6mv2bRzia 0AQNScgbUzwwOhVSyF4g0vg5oIS4TJPtIH3J5S23AqI8AUH8vAjbuuQT3+yZpboJ 7TwuEmE5F+K7zccVg/8wotU/4VY7AibHBiaWthp7g64PmV7Aj716K6kOcNWUeMLe Q2FqbSbOr6ZmWUPbqRO/XAxckztKlDBBAy++qkdaO2vcI+QV09jLNeo/fJr1/n8/ 20i9BmE+DyWlFT+ythpmJgCdWf9VvwRvBcLfXMv0eQYnMU3ELjsqzV5mwzNRhWou KTOKy6UJ8TqLiu5DjFcb =xiUR -----END PGP SIGNATURE----- --vkogqOf2sHV7VnPd--