From patchwork Fri Oct 27 20:27:43 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Machek X-Patchwork-Id: 10030629 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D235A6034B for ; Fri, 27 Oct 2017 20:28:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 873F128FD9 for ; Fri, 27 Oct 2017 20:28:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7BC3628FDD; Fri, 27 Oct 2017 20:28:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_TVD_MIME_EPI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 097CE28FD9 for ; Fri, 27 Oct 2017 20:28:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932474AbdJ0U21 (ORCPT ); Fri, 27 Oct 2017 16:28:27 -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 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 512) id 0806E82417; Fri, 27 Oct 2017 22:27:43 +0200 (CEST) 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-Disposition: inline In-Reply-To: <20171026093115.4bc6ctxjx72ng7ld@earth> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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. > > > > (What do I need to do to get the backlight working?) > > Glad you got it working :) For backlight you can add this > in drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c: > > add the following code at the end of dsicm_probe: > > ----------------------------------------------------------- > mutex_unlock(&ddata->lock); > mutex_lock(&ddata->lock); > ddata->in->ops.dsi->bus_lock(ddata->in); > r = dsicm_wake_up(ddata); > if (!r) > r = 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 .. 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; r = dsicm_dcs_write_1(ddata, DCS_BRIGHTNESS, 0xff); + mdelay(1000); if (r) goto err; @@ -703,6 +704,8 @@ static int dsicm_power_on(struct panel_drv_data *ddata) in->ops.dsi->enable_hs(in, ddata->channel, true); + r = 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; } +#if 0 + mutex_lock(&ddata->lock); + ddata->in->ops.dsi->bus_lock(ddata->in); + r = dsicm_wake_up(ddata); + if (!r) + r = dsicm_dcs_write_1(ddata, DCS_BRIGHTNESS, 100); + ddata->in->ops.dsi->bus_unlock(ddata->in); + mutex_unlock(&ddata->lock); +#endif return 0; err_bl: