From patchwork Fri Jun 8 14:41:37 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Imre Deak X-Patchwork-Id: 10454627 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 31F3E60159 for ; Fri, 8 Jun 2018 14:42:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 167CE29654 for ; Fri, 8 Jun 2018 14:42:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0B6272965B; Fri, 8 Jun 2018 14:42:23 +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=-5.2 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, 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 AE94629654 for ; Fri, 8 Jun 2018 14:42:22 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 057996E116; Fri, 8 Jun 2018 14:42:22 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 29C876E116 for ; Fri, 8 Jun 2018 14:42:21 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Jun 2018 07:42:20 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,490,1520924400"; d="scan'208";a="57628486" Received: from ideak-desk.fi.intel.com ([10.237.72.61]) by orsmga003.jf.intel.com with ESMTP; 08 Jun 2018 07:42:20 -0700 From: Imre Deak To: intel-gfx@lists.freedesktop.org Date: Fri, 8 Jun 2018 17:41:37 +0300 Message-Id: <20180608144137.7943-1-imre.deak@intel.com> X-Mailer: git-send-email 2.13.2 In-Reply-To: <20180608140002.6795-1-imre.deak@intel.com> References: <20180608140002.6795-1-imre.deak@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v3] drm/i915/skl: Add warn about unsupported CDCLK rates X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP While checking workarounds related to the CDCLK PLL, I noticed that the DMC firmware bits for WA#1183 are missing for SKL. After that I clarified with HW people that it's not needed on SKL, since it doesn't support eDP1.4 which would be the only thing requiring the problematic CDCLK clock rates. So in theory we shouldn't ever choose these frequencies, but add an assert in any case for catching such cases and for documentation. v2: - Move the check to skl_set_cdclk and warn whenever using the corresponding VCO freq. (Ville) v3: - Actually check for the platform. (Ville) Cc: Ville Syrjälä Signed-off-by: Imre Deak Reviewed-by: Ville Syrjälä --- drivers/gpu/drm/i915/intel_cdclk.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c index 704ddb4d3ca7..8ed7bd052e46 100644 --- a/drivers/gpu/drm/i915/intel_cdclk.c +++ b/drivers/gpu/drm/i915/intel_cdclk.c @@ -991,6 +991,16 @@ static void skl_set_cdclk(struct drm_i915_private *dev_priv, u32 freq_select, cdclk_ctl; int ret; + /* + * Based on WA#1183 CDCLK rates 308 and 617MHz CDCLK rates are + * unsupported on SKL. In theory this should never happen since only + * the eDP1.4 2.16 and 4.32Gbps rates require it, but eDP1.4 is not + * supported on SKL either, see the above WA. WARN whenever trying to + * use the corresponding VCO freq as that always leads to using the + * minimum 308MHz CDCLK. + */ + WARN_ON_ONCE(IS_SKYLAKE(dev_priv) && vco == 8640000); + mutex_lock(&dev_priv->pcu_lock); ret = skl_pcode_request(dev_priv, SKL_PCODE_CDCLK_CONTROL, SKL_CDCLK_PREPARE_FOR_CHANGE,