From patchwork Fri Nov 18 22:11:56 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paauwe, Bob J" X-Patchwork-Id: 9437433 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 CF84260469 for ; Fri, 18 Nov 2016 22:13:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BDC0D299E6 for ; Fri, 18 Nov 2016 22:13:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AF91629A1E; Fri, 18 Nov 2016 22:13:39 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 47E19295A3 for ; Fri, 18 Nov 2016 22:13:38 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 06DA06EA94; Fri, 18 Nov 2016 22:13:38 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id D22346EA94 for ; Fri, 18 Nov 2016 22:13:36 +0000 (UTC) Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga101.fm.intel.com with ESMTP; 18 Nov 2016 14:13:36 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,660,1473145200"; d="scan'208";a="32369988" Received: from bpaauwe-desk.fm.intel.com ([10.1.134.207]) by orsmga004.jf.intel.com with ESMTP; 18 Nov 2016 14:13:36 -0800 From: Bob Paauwe To: intel-gfx Date: Fri, 18 Nov 2016 14:11:56 -0800 Message-Id: <1479507116-13224-1-git-send-email-bob.j.paauwe@intel.com> X-Mailer: git-send-email 2.7.4 Subject: [Intel-gfx] [PATCH] drm/i915/bxt: Use smaller 8/3X MIPI clock divider value for dual link. X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP For a single link (channel) DSI panel we want to use a larger divider and keep the clock rate down to save power when in DPI/video mode. However when using a dual-link DSI panel this may reduce the clock below what's needed to get a stable display. Use the smaller divider (faster clock) for either DBI/command mode or when using dual link. Signed-off-by: Bob Paauwe --- drivers/gpu/drm/i915/intel_dsi_pll.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dsi_pll.c b/drivers/gpu/drm/i915/intel_dsi_pll.c index 56eff60..9edc57e 100644 --- a/drivers/gpu/drm/i915/intel_dsi_pll.c +++ b/drivers/gpu/drm/i915/intel_dsi_pll.c @@ -414,8 +414,13 @@ static void bxt_dsi_program_clocks(struct drm_device *dev, enum port port, rx_div_lower = rx_div & RX_DIVIDER_BIT_1_2; rx_div_upper = (rx_div & RX_DIVIDER_BIT_3_4) >> 2; - /* As per bpsec program the 8/3X clock divider to the below value */ - if (dev_priv->vbt.dsi.config->is_cmd_mode) + /* + * Set the 8/3X clock to divide by 3 for DBI mode as it needs a + * faster clock than DPI mode. However, dual link panels also + * need the faster clock, even when in DPI mode. + */ + if (dev_priv->vbt.dsi.config->is_cmd_mode || + dev_priv->vbt.dsi.config->dual_link) mipi_8by3_divider = 0x2; else mipi_8by3_divider = 0x3;