From patchwork Thu Apr 5 20:36:01 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Lyude Paul X-Patchwork-Id: 10325327 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 A1F5E60541 for ; Thu, 5 Apr 2018 20:36:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9242629383 for ; Thu, 5 Apr 2018 20:36:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8706429394; Thu, 5 Apr 2018 20:36:13 +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=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 0608A29383 for ; Thu, 5 Apr 2018 20:36:13 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F40FA6E865; Thu, 5 Apr 2018 20:36:11 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7BD0F6E851; Thu, 5 Apr 2018 20:36:10 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 66A80406E8B9; Thu, 5 Apr 2018 20:36:09 +0000 (UTC) Received: from malachite.bss.redhat.com (dhcp-10-20-1-55.bss.redhat.com [10.20.1.55]) by smtp.corp.redhat.com (Postfix) with ESMTP id 78CD510B00B6; Thu, 5 Apr 2018 20:36:06 +0000 (UTC) From: Lyude Paul To: intel-gfx@lists.freedesktop.org Date: Thu, 5 Apr 2018 16:36:01 -0400 Message-Id: <20180405203601.23242-1-lyude@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Thu, 05 Apr 2018 20:36:09 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Thu, 05 Apr 2018 20:36:09 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'lyude@redhat.com' RCPT:'' Subject: [Intel-gfx] [PATCH v2] drm/i915/dp: Send DPCD ON for MST before phy_up 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: , Cc: David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Rodrigo Vivi , Laura Abbott , Dhinakaran Pandiyan Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP When doing a modeset where the sink is transitioning from D3 to D0 , it would sometimes be possible for the initial power_up_phy() to start timing out. This would only be observed in the last action before the sink went into D3 mode was intel_dp_sink_dpms(DRM_MODE_DPMS_OFF). We originally thought this might be an issue with us accidentally shutting off the aux block when putting the sink into D3, but since the DP spec mandates that sinks must wake up within 1ms while we have 100ms to respond to an ESI irq, this didn't really add up. Turns out that the problem is more subtle then that: It turns out that the timeout is from us not enabling DPMS on the MST hub before actually trying to initiate sideband communications. This would cause the first sideband communication (power_up_phy()), to start timing out because the sink wasn't ready to respond. Afterwards, we would call intel_dp_sink_dpms(DRM_MODE_DPMS_ON) in intel_ddi_pre_enable_dp(), which would actually result in waking up the sink so that sideband requests would work again. Since DPMS is what lets us actually bring the hub up into a state where sideband communications become functional again, we just need to make sure to enable DPMS on the display before attempting to perform sideband communications. Changes since v1: - Remove comment above if (!intel_dp->is_mst) - vsryjala - Move intel_dp_sink_dpms() for MST into intel_dp_post_disable_mst() to keep enable/disable paths symmetrical - Improve commit message - dhnkrn Signed-off-by: Lyude Paul Cc: Dhinakaran Pandiyan Cc: Ville Syrjälä Cc: Laura Abbott Cc: stable@vger.kernel.org Fixes: ad260ab32a4d9 ("drm/i915/dp: Write to SET_POWER dpcd to enable MST hub.") --- This email should hopefully actually be picked up by patchwork this time, hooray! drivers/gpu/drm/i915/intel_ddi.c | 6 ++++-- drivers/gpu/drm/i915/intel_dp_mst.c | 2 ++ 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c index a6672a9abd85..c0bf7419e1c1 100644 --- a/drivers/gpu/drm/i915/intel_ddi.c +++ b/drivers/gpu/drm/i915/intel_ddi.c @@ -2324,7 +2324,8 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, intel_prepare_dp_ddi_buffers(encoder, crtc_state); intel_ddi_init_dp_buf_reg(encoder); - intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); + if (!intel_dp->is_mst) + intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); intel_dp_start_link_train(intel_dp); if (port != PORT_A || INTEL_GEN(dev_priv) >= 9) intel_dp_stop_link_train(intel_dp); @@ -2427,7 +2428,8 @@ static void intel_ddi_post_disable_dp(struct intel_encoder *encoder, * Power down sink before disabling the port, otherwise we end * up getting interrupts from the sink on detecting link loss. */ - intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF); + if (!intel_dp->is_mst) + intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF); intel_disable_ddi_buf(encoder); diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c index c3de0918ee13..2493bd1e0e59 100644 --- a/drivers/gpu/drm/i915/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/intel_dp_mst.c @@ -176,6 +176,7 @@ static void intel_mst_post_disable_dp(struct intel_encoder *encoder, */ drm_dp_send_power_updown_phy(&intel_dp->mst_mgr, connector->port, false); + intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF); intel_dp->active_mst_links--; @@ -223,6 +224,7 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder, DRM_DEBUG_KMS("active links %d\n", intel_dp->active_mst_links); + intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); drm_dp_send_power_updown_phy(&intel_dp->mst_mgr, connector->port, true); if (intel_dp->active_mst_links == 0) intel_dig_port->base.pre_enable(&intel_dig_port->base,