From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932642AbdJ0U2a (ORCPT ); Fri, 27 Oct 2017 16:28:30 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:46333 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932470AbdJ0U1q (ORCPT ); Fri, 27 Oct 2017 16:27:46 -0400 Date: Fri, 27 Oct 2017 22:27:43 +0200 From: Pavel Machek To: Sebastian Reichel Cc: Tony Lindgren , pali.rohar@gmail.com, kernel list , linux-arm-kernel , linux-omap@vger.kernel.org, khilman@kernel.org, aaro.koskinen@iki.fi, ivo.g.dimitrov.75@gmail.com, patrikbachan@gmail.com, serge@hallyn.com, abcloriens@gmail.com, clayton@craftyguy.net, martijn@brixit.nl, sakari.ailus@linux.intel.com, filip.matijevic.pz@gmail.com Subject: Backlight on Nokia N900 was Re: 4.13 (and probably all recent) kernels refuse to boot on one Nokia N950, work or another Message-ID: <20171027202743.GA17874@amd> References: <20171025203459.GA22035@amd> <20171025212806.GA21504@atomide.com> <20171026091325.GA26929@amd> <20171026093115.4bc6ctxjx72ng7ld@earth> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="TB36FDmn/VVEgNH/" Content-Disposition: inline In-Reply-To: <20171026093115.4bc6ctxjx72ng7ld@earth> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --TB36FDmn/VVEgNH/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > > I got "uncompressing Linux 4.13" on serial console now, debug LEDs > > blinking, and if I use a flashlight, I see output on the screen, too. > >=20 > > (What do I need to do to get the backlight working?) >=20 > Glad you got it working :) For backlight you can add this > in drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c: >=20 > add the following code at the end of dsicm_probe: >=20 > ----------------------------------------------------------- > mutex_unlock(&ddata->lock); > mutex_lock(&ddata->lock); > ddata->in->ops.dsi->bus_lock(ddata->in); > r =3D dsicm_wake_up(ddata); > if (!r) > r =3D dsicm_dcs_write_1(ddata, DCS_BRIGHTNESS, 100); > ddata->in->ops.dsi->bus_unlock(ddata->in); > mutex_unlock(&ddata->lock); > ----------------------------------------------------------- Ok, I tried that, and did not help. I also tried removing first mutex_unlock(), since that's unbalanced and strange. Did not work. So I commented it out with #if 0, and tried more hacks, but no luck :-(. (I still see the display.. but no backlight so reading it is =2E. difficult.) Best regards, Pavel diff --git a/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c b/drivers/gpu/= drm/omapdrm/displays/panel-dsi-cm.c index 8f74633..c0bbb42 100644 --- a/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c +++ b/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c @@ -668,6 +668,7 @@ static int dsicm_power_on(struct panel_drv_data *ddata) goto err; =20 r =3D dsicm_dcs_write_1(ddata, DCS_BRIGHTNESS, 0xff); + mdelay(1000); if (r) goto err; =20 @@ -703,6 +704,8 @@ static int dsicm_power_on(struct panel_drv_data *ddata) =20 in->ops.dsi->enable_hs(in, ddata->channel, true); =20 + r =3D dsicm_dcs_write_1(ddata, DCS_BRIGHTNESS, 0xff); + return 0; err: dev_err(&ddata->pdev->dev, "error while enabling panel, issuing HW reset\= n"); @@ -1396,6 +1399,15 @@ static int dsicm_probe(struct platform_device *pdev) goto err_bl; } =20 +#if 0=09 + mutex_lock(&ddata->lock); + ddata->in->ops.dsi->bus_lock(ddata->in); + r =3D dsicm_wake_up(ddata); + if (!r) + r =3D dsicm_dcs_write_1(ddata, DCS_BRIGHTNESS, 100); + ddata->in->ops.dsi->bus_unlock(ddata->in); + mutex_unlock(&ddata->lock); +#endif return 0; =20 err_bl: --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --TB36FDmn/VVEgNH/ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlnzlr8ACgkQMOfwapXb+vLJLwCgq2AOn0Ts4O0AgBf2TsWT5oWu RdIAoJr4a0ERZaXo0OKJEMkef1Q+OBIn =DKPW -----END PGP SIGNATURE----- --TB36FDmn/VVEgNH/--