From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) (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 6D2F13A783C for ; Thu, 19 Mar 2026 08:40:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773909638; cv=none; b=IlrfgyGXPbJRLbYosKR6p7bZrAmnrx/q2f4rhavGDLVphJwmPSjB03A6bzZbAFYh6YqSc+8+eq3A0iQ5duLqtqYhGnt+UWq326omQ0A/nRLeXA+4p/RKy9ByduOTi0HOExsYMcGHpXOiKa6OND3RXNh6xAcA9MGSQHtC7RfNG7g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773909638; c=relaxed/simple; bh=oJGZOLOUeEinYwd+OPWiXnsex5raaI8UMVp7k8OFfwM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=l/LUwCAlOJQau30EjPge4Ge5LteDPtl8dKSttBK4qS5sTCVjM1hrOT/qZZT0emqRipiFaMR6vnLvel3Tm+123EUHcBglXCLSN3KO67vW97lIXJrp7WziPaap1wOQX6FrvzUaJt49YDtQVRcS19zUNjwGW+EL5AkPFhTPH8D+hC4= 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=GaGu55Zf; arc=none smtp.client-ip=198.175.65.10 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="GaGu55Zf" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1773909637; x=1805445637; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=oJGZOLOUeEinYwd+OPWiXnsex5raaI8UMVp7k8OFfwM=; b=GaGu55Zfm98FjfAbn10ajXpIlFAh+kCFvi/EqPq8Q9VGWgiFK24lSU+b GCcv9qaBQHHeH75Tsj7+DqOwVGIxD3GHioymRoS9FVgRa1rN7BaY0FZpS bEsIi5K70VzwvX871nwh35RYiwwG0kNH2/38HBqLWC65lkyFGTnHo/ZBZ /sT1oI32Wm6b7RnabwAXpJYjgpujQQEwRsYYGwYkWk9CvCTGpOp8+rMpP UYuMBay9q978rFtIExQZSKXgY5VYFWRY//Haco6gHyNBcYI7YcRw99KpL SyMXsYOL9wFkfmyZxwT6mtinvdFhcA1jY0E09IRKZNhgZtP62+MTQXOM9 g==; X-CSE-ConnectionGUID: OgKn6YCMTYOKSg/H6gLfKQ== X-CSE-MsgGUID: lzww/AsAQnmPHaiQn4cNTQ== X-IronPort-AV: E=McAfee;i="6800,10657,11733"; a="92358616" X-IronPort-AV: E=Sophos;i="6.23,129,1770624000"; d="scan'208";a="92358616" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Mar 2026 01:40:36 -0700 X-CSE-ConnectionGUID: u/Xu2jd3TBmZRJFOqfQ2zg== X-CSE-MsgGUID: Gz1rqaMNRlGvEmFZyx0HFg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,129,1770624000"; d="scan'208";a="227839932" Received: from abityuts-desk.ger.corp.intel.com (HELO [10.245.244.144]) ([10.245.244.144]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Mar 2026 01:40:34 -0700 Message-ID: <903fa309-775c-4562-bbf2-01ef8ac88cc7@linux.intel.com> Date: Thu, 19 Mar 2026 10:40:31 +0200 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: correctly handling EPROTO To: Alan Stern , Michal Pecio Cc: Oliver Neukum , Thinh Nguyen , =?UTF-8?Q?Bj=C3=B8rn_Mork?= , USB list References: <437037d6-3fe1-4f81-b74a-21bea00725e0@rowland.harvard.edu> <0b45d0e4-53f8-4960-b41c-63639b496dac@suse.com> <4f8b9942-307b-4c31-86f3-1b7b20b34a16@rowland.harvard.edu> <87a692e2-559a-4765-8321-a422751d3589@suse.com> <4ada5d68-56f1-41b7-82d9-463901c927db@rowland.harvard.edu> <8a14fe29-0d92-4ce5-a7e2-2c084c710727@suse.com> <20260318223851.1f6d07d7.michal.pecio@gmail.com> <4a35e3dc-620a-4596-9bf3-783865f29e8f@rowland.harvard.edu> Content-Language: en-US From: Mathias Nyman In-Reply-To: <4a35e3dc-620a-4596-9bf3-783865f29e8f@rowland.harvard.edu> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 3/19/26 03:56, Alan Stern wrote: > Just to be clear, are you saying there's no way for an xHC to restart a > (host-side) halted non-SuperSpeed endpoint without setting the toggle > back to 0? There is. A reset endpoint command with a TSP flag (transfer state preserve) clear the host side halt and preserve the toggle state. It's used for soft-retry purposes, retrying a transfer after a transaction error. This is also the only use-case described in xHCI specification. Unclear what happens if we clear the host side halt, preserving the toggle, and then ask host to move to the next URB Could be worth giving people a way to try it out somehow. Maybe option to enable it via debugfs, maybe a quirk, or event just provide a patch. See how different xHC hosts behave -Mathias