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 34DAEC3064D for ; Fri, 28 Jun 2024 07:36:40 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B494310E0E3; Fri, 28 Jun 2024 07:36:39 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="Se8RrErC"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) by gabe.freedesktop.org (Postfix) with ESMTPS id CCFAA10E10E for ; Fri, 28 Jun 2024 07:36:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1719560199; x=1751096199; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=08mcPC3xjeYJFsS7dB0F79IrG5h2rvjd9xiSKKLM4sk=; b=Se8RrErC1+M8z/7n35FaGns1zSLSJRDhdsDLGUKy1c593NeKcu0rQSyj GPr5gC7nN6RVjcHkABB2eSTmQlGa0Kp7K0dHmt2kcId6E46Rw+LGuGB8V dNynH2D9mOJCjJoCIuUp7ICtlbxamgCE56YCcNyzBzBE38OenygJqW2LB adtCikv54gMf/wSew/oA9oxss150pP+VFeK921OhXkCE8hxznSX35v80U u+BOnkqN1DDVywX7d+5buU2Sx5u8gGjEHcCCn3Qa9L2rMip5xGDcf4a9s hMBLoshmj3ATPpqkcN+DoEo1jZzWPWlXqWmFVZ6SqNb3QDS5TzdVTfMr+ Q==; X-CSE-ConnectionGUID: tz/aFDeDTn2ipNm2bo1cZg== X-CSE-MsgGUID: s5S0USDmTsGnUzzFfdRDzQ== X-IronPort-AV: E=McAfee;i="6700,10204,11116"; a="27863734" X-IronPort-AV: E=Sophos;i="6.09,168,1716274800"; d="scan'208";a="27863734" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jun 2024 00:36:38 -0700 X-CSE-ConnectionGUID: m092QRnwRLWSTMvG81Sqnw== X-CSE-MsgGUID: vSWGFNNMTDmOWU54xcCn+Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.09,168,1716274800"; d="scan'208";a="49127957" Received: from lfiedoro-mobl.ger.corp.intel.com (HELO localhost) ([10.245.246.189]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jun 2024 00:36:36 -0700 From: Jani Nikula To: Ben Kao , intel-gfx@lists.freedesktop.org Cc: Ben Kao Subject: Re: [PATCH v1] drm/i915/dp: Modify DP lane count from DPCD reading In-Reply-To: <20240628073013.17233-1-ben.kao@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20240628073013.17233-1-ben.kao@intel.com> Date: Fri, 28 Jun 2024 10:36:32 +0300 Message-ID: <87o77lbjsv.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain 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: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Fri, 28 Jun 2024, Ben Kao wrote: > We found that the external monitor would be failed to display > when hot-plug with dual Type-C USB cable on Dell WD19DC dock. > Due to the host would receive 2 lanes setting when the first HPD, > then receive 4 lanes setting later, but the host only sets 2 lanes > DP and skips to set 4 lanes DP. I modify DP lane count if the > current DP lane count is not the same as DPCD reading. > > Signed-off-by: Ben Kao Please file a bug according to [1]. BR, Jani. [1] https://drm.pages.freedesktop.org/intel-docs/how-to-file-i915-bugs.html > --- > drivers/gpu/drm/i915/display/intel_dp.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c > index 5b3b6ae1e3d7..a9b9023c6744 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp.c > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > @@ -5545,6 +5545,12 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp) > if (!intel_dp_get_dpcd(intel_dp)) > return connector_status_disconnected; > > + /* lanes count changed */ > + if (intel_dp->lane_count != drm_dp_max_lane_count(intel_dp->dpcd)) { > + intel_dp->lane_count = drm_dp_max_lane_count(intel_dp->dpcd); > + return connector_status_disconnected; > + } > + > intel_dp->mst_detect = intel_dp_mst_detect(intel_dp); > > /* if there's no downstream port, we're done */ -- Jani Nikula, Intel