From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7CE508287E; Mon, 27 Apr 2026 05:13:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777266840; cv=none; b=rJMg0Frbg7sO7/jDSwPf5FLl7QYYuCmqEzGe/DorgO99uMU20jxSLAXqyXNRw1fDtma4zQK14DImUABLNYp3rSK1yjXe7ZZlptU+b3+A+cMivDFOnrtM+6RvKEqVgzsI9Bu0Rz9B3QKEuvNnfCOXTEP7j70ak+LLgUw8d/hlQOI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777266840; c=relaxed/simple; bh=jRVANuSdYsgL+ISJyCcZ5z6lO1JXyPOdRhnN3tC2UGc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VpSH/lq8pA0FslcLCseC+qH59PfJaVjNdfjt+26y8nWGMtCZjHImkkUCaKYyg+Pk/WdddVl5nmHiFnzaj3IuZwiyDynYMH8gmBgo5BZlw13xSIF6PXx5odcWf8ULlinoYfn/gRWHuFdiZvzcUdnbNn+6/RLGdzsx6F9jaNJu6N4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=ZpBAvprD; arc=none smtp.client-ip=198.175.65.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="ZpBAvprD" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1777266838; x=1808802838; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=jRVANuSdYsgL+ISJyCcZ5z6lO1JXyPOdRhnN3tC2UGc=; b=ZpBAvprDSgbgChusyEDMZj/xoGWGrdR5pCxh3RDhlsYTMlSH8Ru8kUy7 b2LewB1INTlh1Z9Wkcj91aFKWj+bsjnjh56S4GMaqdXSp91y0k7VOWsWW qgwGviAqCgx4cXg3o6mm60pI3Ocm62064XY76nPm2Lyh2rOooTN4uZCoY vbRtCsAAQ9hS6zoAZ3HhcCnk/XT51rXCmLeeXtJgvYGgMh2W+PfuSC51R gYU41sXwPSUDoVFpyC+7GhZ6xrVHYiTokcA8Jf3A9pwmnOdGRfYQ0x0HM rI5ccRRYG7FU6AoSXLR+4gJ55urG0gEdlMH+Gu+g870aw38pvu09CSe1N w==; X-CSE-ConnectionGUID: lgsepch+Rzufmq5NN6nxQA== X-CSE-MsgGUID: n7zCATLXQXyWdKDvY0QBAA== X-IronPort-AV: E=McAfee;i="6800,10657,11768"; a="88460492" X-IronPort-AV: E=Sophos;i="6.23,201,1770624000"; d="scan'208";a="88460492" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by orvoesa103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Apr 2026 22:13:58 -0700 X-CSE-ConnectionGUID: 63G6Xh74TaiXaHR5p8IfXg== X-CSE-MsgGUID: OgRtFD1MRJC+N+PN+q2NpA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,201,1770624000"; d="scan'208";a="228964801" Received: from black.igk.intel.com ([10.91.253.5]) by fmviesa006.fm.intel.com with ESMTP; 26 Apr 2026 22:13:56 -0700 Received: by black.igk.intel.com (Postfix, from userid 1001) id 138C295; Mon, 27 Apr 2026 07:13:55 +0200 (CEST) Date: Mon, 27 Apr 2026 07:13:55 +0200 From: Mika Westerberg To: Konrad Dybcio Cc: Andreas Noever , Mika Westerberg , Yehezkel Bernat , usb4-upstream@oss.qualcomm.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Konrad Dybcio Subject: Re: [PATCH v2] thunderbolt: debugfs: Don't stop reading SB registers if just one fails Message-ID: <20260427051355.GJ557136@black.igk.intel.com> References: <20260413-topic-tbt_sb_debugfs-v2-1-97a23d4d0568@oss.qualcomm.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260413-topic-tbt_sb_debugfs-v2-1-97a23d4d0568@oss.qualcomm.com> On Mon, Apr 13, 2026 at 11:02:43AM +0200, Konrad Dybcio wrote: > From: Konrad Dybcio > > The GEN4 TxFFE register is not part of the USB4 v1.0 specification, so > understandably some pre-USB4v2 retimers (like the Parade PS8830) don't > seem to implement it. > > The immediate idea to counter this would be to introduce a version > check for that specific register, but on a second thought, the current > flow only returns a quiet -EIO if there's any failures, without hinting > at what the actual problem is. > > To take care of both of these issues, simply print an error line for > each SB register read that fails and go on with attempting to read the > others. > > Note that this is not quite in-spec behavior ("The SB Register Space > registers shall have the structure and fields described in Table 4-17. > Registers not listed in Table 4-20 are undefined and shall not be > used."), but it's the easiest fix that shouldn't have real-world bad > side effects. > > Fixes: 6d241fa00159 ("thunderbolt: Add sideband register access to debugfs") > Signed-off-by: Konrad Dybcio Applied to thunderbolt.git/next, thanks!