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 570CCC021B8 for ; Wed, 26 Feb 2025 12:55:39 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1FAE610E8E5; Wed, 26 Feb 2025 12:55:39 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="APsAFkvW"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) by gabe.freedesktop.org (Postfix) with ESMTPS id E395A10E8E5; Wed, 26 Feb 2025 12:55:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1740574537; x=1772110537; h=from:to:subject:in-reply-to:references:date:message-id: mime-version; bh=Ywl2Ct7g4Ldxupl9V0Ej7RkVUzFHOgFirpHcWev5uaM=; b=APsAFkvWq4ivkMML2YirUui+P6m4u5T8C5iZkqZOuEUWa72jR1Cj47yq V1VWhbN4ml4bb9MvvIV+9zWULPXMvYhBC2DlksOhp1JD3vwv38AflQ+7k 6tkxgRS7PkZ4zWZa3UOCvkFQtKRoj50+GXlLuC0iq8qJOxZ6WX69Iahe0 KqHBmxq/budQ8fnk0+Yi4rk76y/2ujxsZ7GskVnyX47qbKbg+fDF+SkPO ELKMQglJD/UKLZR/IyBhhKjdRUV6nUupJ9PfLxoFgDLfxJ2wy/t+6gODV uH9MkgAuG0DXJ0fpN8b292mwqYAs1BkpHAWueD8d83tf2MdiJ4o3phWFn Q==; X-CSE-ConnectionGUID: nskhOHRfQryWNUQ1M+v/6A== X-CSE-MsgGUID: 3UWPdh/KR0esVDmoKn5UXA== X-IronPort-AV: E=McAfee;i="6700,10204,11357"; a="52407708" X-IronPort-AV: E=Sophos;i="6.13,317,1732608000"; d="scan'208";a="52407708" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Feb 2025 04:55:37 -0800 X-CSE-ConnectionGUID: ppKd086VQg6FFNPVp9URJA== X-CSE-MsgGUID: 4pwH1a54R/CgFkaoyvF+2g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.13,317,1732608000"; d="scan'208";a="121793070" Received: from bergbenj-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.246.123]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Feb 2025 04:55:35 -0800 From: Jani Nikula To: Imre Deak , intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org Subject: Re: [PATCH 0/5] drm/dp: Fix link training interrupted by HPD pulse In-Reply-To: <20250224193115.2058512-1-imre.deak@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20250224193115.2058512-1-imre.deak@intel.com> Date: Wed, 26 Feb 2025 14:55:32 +0200 Message-ID: <87jz9c50hn.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On Mon, 24 Feb 2025, Imre Deak wrote: > This patchset fixes a problem during Display Port link training, where > the link training is interrupted by a short HPD pulse generated by the > sink. Generally the sink signals a bad link state via such short pulses, > but the sink should prevent such signaling during link training. > > Some sinks do generate a short pulse as above during link training, or a > pulse generated before the link training started may be handled from a > scheduled work during link training. Such a handling may interfere with > the link training (see patch 3 for the reason), so this patchset > prevents the handling of pulses during link training. I'm wondering if this series is made unnecessarily complicated by blocking the hotplug handling at the hpd pin level, while what is actually needed is blocking at the encoder level. I believe that would be simpler too. Thoughts? BR, Jani. > > Imre Deak (5): > drm/i915/hpd: Let an HPD pin be in the disabled state when handling > missed IRQs > drm/i915/hpd: Add support for suspending the IRQ handling on an HPD > pin > drm/i915/dp: Fix link training interrupted by a short HPD pulse > drm/i915/dp: Queue a link check after link training is complete > drm/i915/crt: Use intel_hpd_suspend/resume() instead of > intel_hpd_disable/enable() > > drivers/gpu/drm/i915/display/intel_crt.c | 7 +- > .../gpu/drm/i915/display/intel_display_core.h | 2 + > .../drm/i915/display/intel_dp_link_training.c | 23 +- > drivers/gpu/drm/i915/display/intel_hotplug.c | 264 ++++++++++++++---- > drivers/gpu/drm/i915/display/intel_hotplug.h | 5 +- > 5 files changed, 237 insertions(+), 64 deletions(-) -- Jani Nikula, Intel