From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [BISECTED, REGRESSION] v4.12-rc: omapdrm fails to probe on Nokia N900 Date: Tue, 4 Jul 2017 17:09:02 +0200 Message-ID: <20170704150902.GB10703@localhost> References: <20170614221133.k7gmbzzjsbmbjgbc@darkstar.musicnaut.iki.fi> <20170629185013.aec7qhvrl3waifww@darkstar.musicnaut.iki.fi> <20170630085851.j5apctivufhmhp64@darkstar.musicnaut.iki.fi> <5bc9976e-228c-5cba-c2ae-bfc5135f17a0@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT Return-path: Content-Disposition: inline In-Reply-To: <5bc9976e-228c-5cba-c2ae-bfc5135f17a0@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Tomi Valkeinen Cc: Aaro Koskinen , Peter Ujfalusi , Tony Lindgren , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, dri-devel@lists.freedesktop.org, Laurent Pinchart List-Id: linux-omap@vger.kernel.org Hi! > >>>> Are you sure it doesn't probe? It fails the omapdss_stack_is_ready() > >>>> check? > >>> > >>> It appears the reason was that I didn't have > >>> CONFIG_DRM_OMAP_CONNECTOR_ANALOG_TV enabled. > >>> > >>> I think that's wrong. I don't own an analog TV, so why should I enable > >>> such option to get device's built-in display working? > >> > >> Indeed. Unfortunately I don't have a solution for that. > >> > >> DRM doesn't support adding devices after probe. So at omapdrm probe time > >> we have to decide which displays to use. In the dts file, n900 defines > >> the lcd and analog tv. omapdrm sees those, and, of course, must wait > >> until their respective drivers have probed. If you don't have the > >> display driver enabled, it's never loaded and omapdrm never probes as it > >> keeps waiting for those. > > > > Could you at least print some kind of message early in the boot ("omapdrm > > is waiting for drivers for display x and y")? > > That could be quite spammy. omapdrm will defer probe if the displays are > not present, and the deferred probing machinery will then cause a new > omapdrm probe later. That can happen a lot of times before the drivers > are there. Well doing printk just once should not be a problem...? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html