Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751896AbdF3JiJ (ORCPT ); Fri, 30 Jun 2017 05:38:09 -0400 Received: from emh02.mail.saunalahti.fi ([62.142.5.108]:34318 "EHLO emh02.mail.saunalahti.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751666AbdF3JiI (ORCPT ); Fri, 30 Jun 2017 05:38:08 -0400 Date: Fri, 30 Jun 2017 12:37:59 +0300 From: Aaro Koskinen To: Tomi Valkeinen Cc: Peter Ujfalusi , Tony Lindgren , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, dri-devel@lists.freedesktop.org, Laurent Pinchart Subject: Re: [BISECTED, REGRESSION] v4.12-rc: omapdrm fails to probe on Nokia N900 Message-ID: <20170630093759.okfhlkmcz74ow7lk@darkstar.musicnaut.iki.fi> References: <20170614221133.k7gmbzzjsbmbjgbc@darkstar.musicnaut.iki.fi> <20170629185013.aec7qhvrl3waifww@darkstar.musicnaut.iki.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2035 Lines: 62 Hi, On Fri, Jun 30, 2017 at 11:47:55AM +0300, Tomi Valkeinen wrote: > > So, I don't know... I guess I need to try to invent some horrible hacks > > around the driver to somehow manage the omap3 problems. Perhaps > > disabling/enabling the outputs when sync lost happens... > > Well, I tried that (attached), but it didn't work either. For some > reason the error worker seems to stop after the disable. Possibly the > irq flood keeps it from running, so maybe it should catch all the errors > (I see underflows too). > > Sorry, but I can't use more time on this today, and I'm leaving for > vacation today. I hope Laurent can help during my absence. > > We could try reverting the patch you mention, but I think it doesn't > cause the problem. True, reverting the patch only allows me to use display without connector. And apparently it just works by luck. > Did you have CONFIG_DRM_OMAP_CONNECTOR_ANALOG_TV enabled earlier when > things worked? No. I have never enabled it before, I didn't even know it was supported by the mainline. > If you didn't, and the dts did not contain display aliases, I think the > omapdrm may have started without TV. So maybe the TV side is the culprit, > somehow (I couldn't find anything when I looked at that side either). Could be. Here is the summary from my testing: 0) v4.17-rc7 + connector disabled ==> nothing happens, omapdrm waits forever for connector driver 1) v4.17-rc7 + connector disabled + Revert "drm/omap: Use omapdss_stack_is_ready()" ==> LCD error flood, system unusable 2) v4.17-rc7 + connector disabled + Revert "drm/omap: Use omapdss_stack_is_ready()" + Apply "drm/omap: work-around for omap3 display enable" ==> display works! 3) v4.17-rc7 + connector enabled + Revert "drm/omap: Use omapdss_stack_is_ready()" + Apply "drm/omap: work-around for omap3 display enable" ==> LCD error flood, system unusable 4) v4.17-rc7 + connector enabled + Apply "drm/omap: work-around for omap3 display enable" ==> LCD error flood, system unusable A.