From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D2348C6FD1F for ; Wed, 22 Mar 2023 11:19:32 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2D1D110E91D; Wed, 22 Mar 2023 11:19:32 +0000 (UTC) Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id DBB6310E91D for ; Wed, 22 Mar 2023 11:19:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1679483969; x=1711019969; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=WNmo57sSnVSBlGinMVbYjG4rKLEc4/chNIdguMbANs8=; b=DJqIPKTaEUxzvyHIdxk0ZbnbYnL21gbaPEJ7bgkoWyqYDvO16w1kIlxV ZU1n4yqujq/XPnW+MgAwJ5b48asAs67AFj0d4pyqUb/JIwBLqwbn2YAQ4 R5Uim5xs677NTUEL9LC27KxSXrENdwjJqBr+MlvIaxOVNAI50JElZndxF uTCo4b0jQa+F+wZG10Ax5JLhu+Im3mN/y21abJWKgkJm/FnlM25J1tvuf u6mTsUjCHUA3sADmWZE1E/SFnWuIppXhMxCPaKRBtIfzMmxiZwkrQGgY0 Uz4cyR7PQPTOAreW8f9GcyqwK0BgS1L3Pp3a8lX2b1dUTKDHC2hApSvm4 A==; X-IronPort-AV: E=McAfee;i="6600,9927,10656"; a="401756312" X-IronPort-AV: E=Sophos;i="5.98,281,1673942400"; d="scan'208";a="401756312" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Mar 2023 04:19:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10656"; a="856072539" X-IronPort-AV: E=Sophos;i="5.98,281,1673942400"; d="scan'208";a="856072539" Received: from ahajda-mobl.ger.corp.intel.com (HELO [10.213.22.233]) ([10.213.22.233]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Mar 2023 04:19:28 -0700 Message-ID: <65970908-9396-dda8-e4b5-746ab24894f4@intel.com> Date: Wed, 22 Mar 2023 12:19:26 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.9.0 Content-Language: en-US To: Imre Deak , intel-gfx@lists.freedesktop.org References: <20230316131724.359612-1-imre.deak@intel.com> <20230316131724.359612-2-imre.deak@intel.com> From: Andrzej Hajda Organization: Intel Technology Poland sp. z o.o. - ul. Slowackiego 173, 80-298 Gdansk - KRS 101882 - NIP 957-07-52-316 In-Reply-To: <20230316131724.359612-2-imre.deak@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Intel-gfx] [PATCH 01/14] drm/i915/tc: Abort DP AUX transfer on a disconnected TC port X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Chris Chiu Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 16.03.2023 14:17, Imre Deak wrote: > On TC ports the 4ms AUX timeout combined with the 5 * 32 retry > attempts during DPCD accesses adds a 640ms delay to each access if the > sink is disconnected. This in turn slows down a modeset during which the > sink is disconnected (for instance a disabling modeset). > > Prevent the above delay by aborting AUX transfers on a TC port with a > disconnected sink. > > The DP 1.4a link CTS (4.2.1.5 Source Device Inactive HPD / Inactive AUX > Test") also requires not to initiate AUX transfers on disconnected DP > ports in general, however this patch doesn't change the behavior on > non-TC ports, leaving that for a follow-up. > > Reported-and-tested-by: Chris Chiu > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8279 > Signed-off-by: Imre Deak > --- > drivers/gpu/drm/i915/display/intel_dp_aux.c | 15 +++++++++++++-- > drivers/gpu/drm/i915/display/intel_tc.c | 15 +++++++++++---- > drivers/gpu/drm/i915/display/intel_tc.h | 1 + > 3 files changed, 25 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c b/drivers/gpu/drm/i915/display/intel_dp_aux.c > index 96967e21c94c2..eb07dc5d87099 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_aux.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c > @@ -205,8 +205,19 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp, > for (i = 0; i < ARRAY_SIZE(ch_data); i++) > ch_data[i] = intel_dp->aux_ch_data_reg(intel_dp, i); > > - if (is_tc_port) > + if (is_tc_port) { > intel_tc_port_lock(dig_port); > + /* > + * Abort transfers on a disconnected port as required by > + * DP 1.4a link CTS 4.2.1.5, also avoiding the long AUX > + * timeouts that would otherwise happen. > + * TODO: abort the transfer on non-TC ports as well. Yes, for all ports this is definitely desirable, for example grep shows about 15000 timeouts per one CI dmesg[1]. At least I hope, this cures the plague. Reviewed-by: Andrzej Hajda [1]: http://gfx-ci.igk.intel.com/tree/drm-tip/CI_DRM_12884/fi-elk-e7500/dmesg0.txt Regards Andrzej > + */ > + if (!intel_tc_port_connected_locked(&dig_port->base)) { > + ret = -ENXIO; > + goto out_unlock; > + } > + } > > aux_domain = intel_aux_power_domain(dig_port); > > @@ -367,7 +378,7 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp, > > intel_pps_unlock(intel_dp, pps_wakeref); > intel_display_power_put_async(i915, aux_domain, aux_wakeref); > - > +out_unlock: > if (is_tc_port) > intel_tc_port_unlock(dig_port); > > diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c > index f45328712bff1..050f998284592 100644 > --- a/drivers/gpu/drm/i915/display/intel_tc.c > +++ b/drivers/gpu/drm/i915/display/intel_tc.c > @@ -768,16 +768,23 @@ void intel_tc_port_sanitize_mode(struct intel_digital_port *dig_port) > * connected ports are usable, and avoids exposing to the users objects they > * can't really use. > */ > +bool intel_tc_port_connected_locked(struct intel_encoder *encoder) > +{ > + struct intel_digital_port *dig_port = enc_to_dig_port(encoder); > + struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev); > + > + drm_WARN_ON(&i915->drm, !intel_tc_port_ref_held(dig_port)); > + > + return tc_port_live_status_mask(dig_port) & BIT(dig_port->tc_mode); > +} > + > bool intel_tc_port_connected(struct intel_encoder *encoder) > { > struct intel_digital_port *dig_port = enc_to_dig_port(encoder); > bool is_connected; > > intel_tc_port_lock(dig_port); > - > - is_connected = tc_port_live_status_mask(dig_port) & > - BIT(dig_port->tc_mode); > - > + is_connected = intel_tc_port_connected_locked(encoder); > intel_tc_port_unlock(dig_port); > > return is_connected; > diff --git a/drivers/gpu/drm/i915/display/intel_tc.h b/drivers/gpu/drm/i915/display/intel_tc.h > index d54082e2d5e8d..93813056043a5 100644 > --- a/drivers/gpu/drm/i915/display/intel_tc.h > +++ b/drivers/gpu/drm/i915/display/intel_tc.h > @@ -17,6 +17,7 @@ bool intel_tc_port_in_dp_alt_mode(struct intel_digital_port *dig_port); > bool intel_tc_port_in_legacy_mode(struct intel_digital_port *dig_port); > > bool intel_tc_port_connected(struct intel_encoder *encoder); > +bool intel_tc_port_connected_locked(struct intel_encoder *encoder); > > u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port); > u32 intel_tc_port_get_pin_assignment_mask(struct intel_digital_port *dig_port);