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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77DB7C433EF for ; Wed, 6 Apr 2022 16:51:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238226AbiDFQxO (ORCPT ); Wed, 6 Apr 2022 12:53:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238323AbiDFQwr (ORCPT ); Wed, 6 Apr 2022 12:52:47 -0400 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D517C11FE07 for ; Wed, 6 Apr 2022 07:56:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1649257017; x=1680793017; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=F/U+cj87UvGy5lLxu2syFQGQxJxfbuLpFf8x7D/NyD4=; b=VysKwanJ++NfYcHoIcpt6ZK34rFJEferTR2GzGrAdqCCtOL4KlqM5a/7 ACzBF1i2PTIOfc034jrtLF6glUgW4EfS5nkH5bYN/bjEGfk+Ll3K6bCyq KvS08MdW6Y07yvVKJBOQea0svTqqxDJA4MFS0kH9T0Z3wiKrQPxDMdlnp kMxkfESx8De47UnT55y9FfZraAwL0HQ5QRNdhUuJusu/MVVOhJXg55Fku 8GjPY2JEUehBZyqBDWG+ywNlUYSJ2PcSAw+dLSUotBAKey6F7gUVkoSmv SBYQIG+yGU1IQqP6BhuqJUTTu1owPkp2VGNk5fZY5CuziCzYVi3xh652Z w==; X-IronPort-AV: E=McAfee;i="6200,9189,10309"; a="243209608" X-IronPort-AV: E=Sophos;i="5.90,240,1643702400"; d="scan'208";a="243209608" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Apr 2022 07:56:54 -0700 X-IronPort-AV: E=Sophos;i="5.90,240,1643702400"; d="scan'208";a="588410796" Received: from lahna.fi.intel.com (HELO lahna) ([10.237.72.162]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Apr 2022 07:56:52 -0700 Received: by lahna (sSMTP sendmail emulation); Wed, 06 Apr 2022 17:56:50 +0300 Date: Wed, 6 Apr 2022 17:56:50 +0300 From: Mika Westerberg To: Brad Campbell Cc: linux-kernel@vger.kernel.org Subject: Re: Apple Thunderbolt Display chaining Message-ID: References: <5dcee6f7-cc8c-e3ce-920c-4ad3f5d77e14@fnarfbargle.com> <7ea44c20-6c65-224f-af7b-aa1bd310d038@fnarfbargle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Wed, Apr 06, 2022 at 10:51:41AM +0800, Brad Campbell wrote: > Both included in-line. > > This is cold boot with the chain plugged in. I've re-added the dbg to > print the link number, and I've included your path discovery debugs. > Boot with chain plugged in, wait for it to settle, unplug and replug. > First head in the chain fails with : > > [ 65.778129] [drm:radeon_dp_link_train [radeon]] *ERROR* displayport link status failed > [ 65.778158] [drm:radeon_dp_link_train [radeon]] *ERROR* clock recovery failed Thanks for the logs! The DP tunnels look pretty much the same except that the Apple EFI CM seems to assign 7 buffers for the AUX RX path first hop whereas we always use 1 buffer. Not sure if that really makes a difference and we could try to use the same number but first, I realized that the PCI resource allocation seems not to work properly. Can you disable PCIe tunneling (if you use Ubuntu/Fedora or similar there is the "Thunderbolt -> Direct Access" switch that you can turn off) and try again? Please also take 'sudo lspci -vv' for the resulting topology. I suspect this might also affect the other issues (the timeouts) you are seeing. Note this makes the peripherals connected to the monitors unusable too.