From patchwork Mon May 23 18:56:54 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: cpaul@redhat.com X-Patchwork-Id: 9132273 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 2F91D60761 for ; Mon, 23 May 2016 18:57:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2660F28219 for ; Mon, 23 May 2016 18:57:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1B3A22824C; Mon, 23 May 2016 18:57:13 +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=unavailable version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C662928219 for ; Mon, 23 May 2016 18:57:12 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0DED36E41C; Mon, 23 May 2016 18:57:06 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTPS id BDF616E420; Mon, 23 May 2016 18:57:04 +0000 (UTC) Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2BB8064064; Mon, 23 May 2016 18:57:04 +0000 (UTC) Received: from ecstaticemu.bos.redhat.com (dhcp-25-142.bos.redhat.com [10.18.25.142]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u4NIv276014350; Mon, 23 May 2016 14:57:02 -0400 From: Lyude To: intel-gfx@lists.freedesktop.org Subject: [PATCH] drm/i915/ilk: Disable SSC for DPLLs if we're not using it Date: Mon, 23 May 2016 14:56:54 -0400 Message-Id: <1464029814-28187-1-git-send-email-cpaul@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 23 May 2016 18:57:04 +0000 (UTC) Cc: stable@vger.kernel.org, "open list:INTEL DRM DRIVERS excluding Poulsbo, Moorestow..., linux-kernel@vger.kernel.org open list" , Daniel Vetter , Lyude X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP Thanks to Ville Syrjälä for pointing me towards the cause of this issue. Unfortunately one of the sideaffects of having the refclk for a DPLL set to SSC is that as long as it's set to SSC, the GPU will prevent us from powering down any of the pipes or transcoders using it. A couple of BIOSes, despite the fact they don't actually need it, enable SSC both in PCH_DREF_CONTROL and on the DPLL configurations. This causes issues on the first modeset, since we don't expect SSC to be left on and as a result, can't successfully power down the pipes or the transcoders using it. Here's an example from this Dell OptiPlex 990: [drm:intel_modeset_init] SSC enabled by BIOS, overriding VBT which says disabled [drm:intel_modeset_init] 2 display pipes available. [drm:intel_update_cdclk] Current CD clock rate: 400000 kHz [drm:intel_update_max_cdclk] Max CD clock rate: 400000 kHz [drm:intel_update_max_cdclk] Max dotclock rate: 360000 kHz vgaarb: device changed decodes: PCI:0000:00:02.0,olddecodes=io+mem,decodes=io+mem:owns=io+mem [drm:intel_crt_reset] crt adpa set to 0xf40000 [drm:intel_dp_init_connector] Adding DP connector on port C [drm:intel_dp_aux_init] registering DPDDC-C bus for card0-DP-1 [drm:ironlake_init_pch_refclk] has_panel 0 has_lvds 0 has_ck505 0 [drm:ironlake_init_pch_refclk] Disabling SSC entirely … later we try committing the first modeset … [drm:intel_dump_pipe_config] [CRTC:26][modeset] config ffff88041b02e800 for pipe A [drm:intel_dump_pipe_config] cpu_transcoder: A … [drm:intel_dump_pipe_config] dpll_hw_state: dpll: 0xc4016001, dpll_md: 0x0, fp0: 0x20e08, fp1: 0x30d07 [drm:intel_dump_pipe_config] planes on this crtc [drm:intel_dump_pipe_config] STANDARD PLANE:23 plane: 0.0 idx: 0 enabled [drm:intel_dump_pipe_config] FB:42, fb = 800x600 format = 0x34325258 [drm:intel_dump_pipe_config] scaler:0 src (0, 0) 800x600 dst (0, 0) 800x600 [drm:intel_dump_pipe_config] CURSOR PLANE:25 plane: 0.1 idx: 1 disabled, scaler_id = 0 [drm:intel_dump_pipe_config] STANDARD PLANE:27 plane: 0.1 idx: 2 disabled, scaler_id = 0 [drm:intel_get_shared_dpll] CRTC:26 allocated PCH DPLL A [drm:intel_get_shared_dpll] using PCH DPLL A for pipe A [drm:ilk_audio_codec_disable] Disable audio codec on port C, pipe A [drm:intel_disable_pipe] disabling pipe A ------------[ cut here ]------------ WARNING: CPU: 1 PID: 130 at drivers/gpu/drm/i915/intel_display.c:1146 intel_disable_pipe+0x297/0x2d0 [i915] pipe_off wait timed out … ---[ end trace 94fc8aa03ae139e8 ]--- [drm:intel_dp_link_down] [drm:ironlake_crtc_disable [i915]] *ERROR* failed to disable transcoder A Later modesets succeed since they reset the DPLL's configuration anyway, but this is enough to get stuck with a big fat warning in dmesg. Normally we'd need to add some sort of ref counting mechanism to the CRTCs so we avoid accidentally trying to shut off a shared resource, but since ignore what the BIOS does anyway and we shut off the refclks before any modesets, this workaround should suffice for now. Cc: stable@vger.kernel.org Signed-off-by: Lyude --- drivers/gpu/drm/i915/intel_display.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index d500e6f..3fb6025 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -8230,7 +8230,8 @@ static void ironlake_init_pch_refclk(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; struct intel_encoder *encoder; - u32 val, final; + int i; + u32 val, temp, final; bool has_lvds = false; bool has_cpu_edp = false; bool has_panel = false; @@ -8369,6 +8370,22 @@ static void ironlake_init_pch_refclk(struct drm_device *dev) I915_WRITE(PCH_DREF_CONTROL, val); POSTING_READ(PCH_DREF_CONTROL); udelay(200); + + /* Unset SSC as the refclk for all of the DPLLs */ + for (i = 0; i < dev_priv->num_shared_dpll; i++) { + temp = I915_READ(PCH_DPLL(i)); + + if (!(temp & PLLB_REF_INPUT_SPREADSPECTRUMIN)) + continue; + + DRM_DEBUG_KMS("Disabling SSC refclk for %s\n", + dev_priv->shared_dplls[i].name); + + /* Change refclk to DREFCLK */ + temp &= ~PLL_REF_INPUT_MASK; + + I915_WRITE(PCH_DPLL(i), temp); + } } BUG_ON(val != final);