From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6658DC433E1 for ; Wed, 5 Aug 2020 19:57:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5124922B42 for ; Wed, 5 Aug 2020 19:57:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728667AbgHET5A (ORCPT ); Wed, 5 Aug 2020 15:57:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728004AbgHEQoM (ORCPT ); Wed, 5 Aug 2020 12:44:12 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE9F7C061A15 for ; Wed, 5 Aug 2020 04:07:25 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: sre) with ESMTPSA id 3A063296BA6 Received: by earth.universe (Postfix, from userid 1000) id 5CF5D3C0C80; Wed, 5 Aug 2020 13:07:18 +0200 (CEST) Date: Wed, 5 Aug 2020 13:07:18 +0200 From: Sebastian Reichel To: "H. Nikolaus Schaller" Cc: Tomi Valkeinen , Laurent Pinchart , Tony Lindgren , Linux-OMAP , Jyri Sarha , kernel@pyra-handheld.com, Discussions about the Letux Kernel , David Shah Subject: Re: module_mipi_dsi_driver panel with omapdrm? Message-ID: <20200805110718.zvjbmv3ftgpcudly@earth.universe> References: <20200706143613.GS37466@atomide.com> <20200707180115.GB5849@atomide.com> <6E0A9415-9AB5-48D9-9E61-12D20655D04D@goldelico.com> <20200724012411.GJ21353@pendragon.ideasonboard.com> <7023EB05-DC29-4D42-84C8-F0D14B50467D@goldelico.com> <3326D023-8D7D-4B97-90B3-E05392A187DC@goldelico.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="nrp2o7orvviodf7g" Content-Disposition: inline In-Reply-To: <3326D023-8D7D-4B97-90B3-E05392A187DC@goldelico.com> Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org --nrp2o7orvviodf7g Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Wed, Aug 05, 2020 at 11:25:58AM +0200, H. Nikolaus Schaller wrote: > > Am 04.08.2020 um 14:43 schrieb Tomi Valkeinen : > > On 01/08/2020 16:43, H. Nikolaus Schaller wrote: > >> Fortunately David did fix the broken "reboot" for OMAP5 (when using ti= mer8). > >> Now I could run an unattended bisect session for the MIPI DSI panel dr= iver > >> to find as the first bad commit: > >>=20 > >> commit e7e67d9a2f1dd2f938adcc219b3769f5cc3f0df7 > >> Author: Laurent Pinchart > >> Date: Wed Feb 26 13:24:59 2020 +0200 > >>=20 > >> drm/omap: Switch the HDMI and VENC outputs to drm_bridge > >>=20 > >> This was merged through v5.7-rc1. The problem persists since then up > >> to v5.8-rc7 and likely also to v5.9. > >>=20 > >> What I guess from the change hunks is that this is the critical one: > >>=20 > >> diff --git a/drivers/gpu/drm/omapdrm/dss/output.c b/drivers/gpu/drm/om= apdrm/dss/output.c > >> index 9ba7cc8539a1..ce21c798cca6 100644 > >> --- a/drivers/gpu/drm/omapdrm/dss/output.c > >> +++ b/drivers/gpu/drm/omapdrm/dss/output.c > >> @@ -60,6 +60,11 @@ int omapdss_device_init_output(struct omap_dss_devi= ce *out, > >> } > >>=20 > >> if (local_bridge) { > >> + if (!out->bridge) { > >> + ret =3D -EPROBE_DEFER; > >> + goto error; > >> + } > >> + > >> out->next_bridge =3D out->bridge; > >> out->bridge =3D local_bridge; > >> } > >>=20 > >> Since I have not seen a reference to an omap DSI bridge driver in upst= ream kernels > >> I would assume that out->bridge is NULL and therefore probing is defer= red forever > >> and the old MIPI DSI driver (which is still there) is no longer operat= ional. > >>=20 > >> This is consistent with that our (old omapdrm) panel driver is no long= er probed. > >=20 > > What happens? Do you get any displays? Or no displays at all? Do > > you get an error print? > >=20 > > As Sebastian said, this shouldn't prevent DSI from probing. I > > don't see anything in the commit that might affect DSI. >=20 > Yes, that is indeed strange. The only potential direct reason I could ima= gine is the > additional test for out-bridge, but with Sebastian's explanation it is not > even called for DSI. >=20 > Maybe it is a false report by git bisect because this patch enables a cha= nge somewhere > else for the first time, which affects the DSI setup indirectly. >=20 > I have seen that there now is a similar, but not identical report for the= N900 panel. Note, that the N900 has an SDI panel, which is different from DSI. > > Does the board have other display outputs? HDMI? If yes, could > > you try with HDMI disabled, e.g. set its status to "disabled" in > > the .dts. >=20 > My good/bad indicator is that there is no /dev/fb0 created any more. I ha= ve not > checked for HDMI but it is likely also missing then. Basically it stopped= working > with v5.7-rc1 (as the basis where we add our private panel driver, some P= MU/charger > driver, DTS on top) and bisect did report this commit. >=20 > Unfortunately I currently can't do tests on real hardware and play around= with printk > in the code for the next weeks. Or partially reverting the patch step by = step to see > which change has an influence. So it might be HDMI (or VENC) not probing successfully and then resulting in -EPROBE_DEFER for omapdrm with no connection to DSI at all. I suggest to disable all non-DSI video devices in devicetree and check if this results in DSI panel coming up. -- Sebastian --nrp2o7orvviodf7g Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEE72YNB0Y/i3JqeVQT2O7X88g7+poFAl8qkuMACgkQ2O7X88g7 +pqQuxAApKhSuuUzl1J7Tc/dmjgUcKt4W9Y+0A/Kkr4M4BUVKJtfqfoj3J5+7e1a 5pwjpUEML5qBucQVu1GNsiOyccwpP6hq+gGywnC5gWWBXd60KHYUhjPP8xIfofxD xEVlibOWEI23tZJK53j4qcz2mr2lDAkTGEW+bh1QQ9j3wFQ76JJF1c28TlsSBaMK n/afPANev1JLJ8MytnHEFFArJp+0nge3bOZ8gP0j4qiX+EhGz9dGfijhtjyt+LjJ MeS5hfD7/6v4ZgEjMSp3dlAawb8f12W5SGQAriOMwPuCAi7bChhZjnOLgGLq3lvW d4ZaLJz2gLcR1vk627JbP3KM0ynEVjWJ2EV3bKAXqZSod2pL5+zT2q3i642e12vh 4VPf3ZqJE0WRfAOsBeBb5km6ZD9+VJaGSo22FDa8KOPQX2MLWGee+nd6e/BFRI5x geEryLMjWf+HwpGTRYkNhDIMLFiXo1mbXBG6jsde+RosSsiEv91dSSJcGV3ueWOs d77wS7LZDeaBfoZYkfKTx1987gnO182wKgAxkCY16xPjlUjiTyTS51FrUyd/Nbry 2Rc+vXXBA0OjF8fnyh1G3kSdj8jyt8dThxg8wPdotuhvbCjX0jkddUsWZlJ1nVk7 CCKrrPIrZgkrMGbfQ4PXbFa6bg8U8kt1cRIsmWw35Ue3NfbZpN0= =yrQS -----END PGP SIGNATURE----- --nrp2o7orvviodf7g--