From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH] drm/exynos: Make exynos_drm_init() call late during the bootup Date: Wed, 21 May 2014 17:46:23 +0200 Message-ID: <20140521154622.GO2014@ulmo> References: <1400067585-31236-1-git-send-email-ch.naveen@samsung.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="hOh8F6DNH/RZBSFD" Return-path: Received: from mail-ee0-f53.google.com ([74.125.83.53]:61302 "EHLO mail-ee0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751450AbaEUPsl (ORCPT ); Wed, 21 May 2014 11:48:41 -0400 Received: by mail-ee0-f53.google.com with SMTP id c13so1714674eek.40 for ; Wed, 21 May 2014 08:48:40 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1400067585-31236-1-git-send-email-ch.naveen@samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Naveen Krishna Chatradhi Cc: dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, naveenkrishna.ch@gmail.com --hOh8F6DNH/RZBSFD Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, May 14, 2014 at 05:09:45PM +0530, Naveen Krishna Chatradhi wrote: > exynos_drm_init() does probing of various drivers like dp_panel, > hdmi, fimd, mixer, etc in an order and finally binds them together. >=20 > Some of the drm devices (Eg: dp_panel) try to do regulator_get() > and enable few supplies during their probe. > Chances are that, these devices may get probed before the respective > supply/PMIC is hooked. In such cases, dp_panel would continue with > "dummy regulator". Which is not what the system wants. >=20 > Lets give the core connectivity and regulators modules some time > to hookup the supplies before Exynos DRM devices comes into picture. >=20 > Signed-off-by: Naveen Krishna Chatradhi > --- > This change is proposed after > 1. Discussing with I2C/SPI & DMA subsystem maintainers and Others > @ https://lkml.org/lkml/2014/5/9/333 > Trying to change the I2C, SPI and DMA drivers as subsys_initcall() > Which was strictly opposed, as a flaw was found in DRM subsystem. >=20 > 2. -EPROBE_DEFER won't work well with the current sequency of > platform_driver_register()s in exynos_drm_init() Then this is the problem that you need to fix. If the driver doesn't handle -EPROBE_DEFER properly then that means the driver is broken. No amount of initcall ordering can fix this for you. Thierry --hOh8F6DNH/RZBSFD Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAEBAgAGBQJTfMpOAAoJEN0jrNd/PrOh62cP/jn11L6lN8e5GmoSTJxltu9D hi/bvOp8CdlAwJVfxP2gNT/sa0jeLB0eV3SaTeGzq72q2tBZ44EiRP9TJsMnX56c nHZ2HF6xj9ACWtroLFHU3FbciBbMwxEV2Vv1XgHcJrpUzv2hFlGurEK6eMK/9cWO aRQC4IzA/JxRXbwCAy0V6guzPrnuilHqNi6PpUoZJVb1F+ZLAKpqU8HVCoI3mwrs dwqUhbtGkiu04uNHGqRxleex1hQ47LHKkhdeMFKjkejdw8FwSRrD1IG7RjAZmX9m LIkLINCiB1DLS8rODN1zdf9P/jQ7Nu/VlXZIqoDAz24WRO+NyqRpaS6shhEixEit ZNnWgYodKt/BFUY6D1JE6GJslTUoTGL8BALgyM2N92VuYvQF+Jd+j/3mtewzi5DV Dp5W9FLc/t8vIZ/iiTW4dLvVQPOlJ7ydIPikYiSz2GSQq92PjHq4v42jJCYWrrvs 3jJ/y0a8VsH2jh0azzr3BSQEwwzPsD47waW7pzN3uYAF9KfV4QE9xdQBNjoSEAvO VOBPfMNFd7VYIJ5+mTtAvg2TahnOb+qcI8Enyj30R4oaL5jqtug1yQa+BosCDhrj 2z4OPCoIEw+ux1pj0NWazrwW/G2n3gKRAH0kC4TiUbvO4n0ROJ8yMhPu4qq22Wei 7olmZB4GSaSBrhB2niTn =lons -----END PGP SIGNATURE----- --hOh8F6DNH/RZBSFD--