From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.17]) (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 91ABB3DD525; Thu, 10 Sep 2026 09:33:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789032836; cv=none; b=PJkCy4PW94XpH5LtsdwQ+uM9YCi1IZEzCF/xLlvNbm0ciBibF/rN/XazRa9EAO7n7qrlyfg6UczESHVg1b2KWE6dCn9/t0GwNip1ig8bXd+DCdlxikhzEtJYf9MAdmEcB6ZQDjqVPoQNO+b5wmATsa9nIf956wI0vBTnVwNy974= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789032836; c=relaxed/simple; bh=FjcDcqvU0235HfXhQqh3BNVRPpVFE3oJFo7uUnHGA88=; h=From:Date:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=j79tny9sOKOC8csXtjX0sySq32l3SvVfTxPP2J8rF3aKb+AT9LnQ2RpBxpKITfOVFIZGt1yohdSxiQjIKnGZTXrV5ILRpC3QlDyF+yX+QjyLmQhFhMKpsywznRLvASz96WP0L5ahXJ0VvBLGpgBnuTuQJc8TGg1LN9+3T36ZW9o= 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=cY8PFmEo; arc=none smtp.client-ip=198.175.65.17 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="cY8PFmEo" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1789032833; x=1820568833; h=from:date:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=FjcDcqvU0235HfXhQqh3BNVRPpVFE3oJFo7uUnHGA88=; b=cY8PFmEozMPmjnX10Z3PYZoWfUn60dxbjVOu5MErTglZ+2bT4eNbcFsr Ep4+X3Z3OPA1ivNK4wk6UGsYfwWAll9MIlGFwvI1zWqFeFfbGuthNI944 XBCzvfvpQaLJH7jqNMHn7zpKTWMbRy1+5l/qp571/2oHDLr0LP9rXErQY Olepj3FGmGSUpBa5Rx3pXNKEzOhEWAEIwrBzSsHc2WdIMx/Le02yGV346 9xgbCmKqEWbIQFZF18Lpc4Zk7Ce0K3nwjOVakvG9qZJP2z3GYdvS4VF+l YoKhhTYd/IlnYZJZMJt8Gvkfe0JODFVUzGpTO2yCat7VvwFJktLJBBVhk A==; X-CSE-ConnectionGUID: IBZ2LolpTYmMfkJPoQqhVQ== X-CSE-MsgGUID: G9L0dvZAR7+xJiGGNR1M1Q== X-IronPort-AV: E=McAfee;i="6800,10657,11900"; a="89509912" X-IronPort-AV: E=Sophos;i="6.27,95,1787036400"; d="scan'208";a="89509912" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by orvoesa109.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Sep 2026 02:33:50 -0700 X-CSE-ConnectionGUID: 3jn/nBKeSJK4lhAyBYfZeA== X-CSE-MsgGUID: IkjzOK7hQjS96BFYssBhzg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,95,1787036400"; d="scan'208";a="272089790" Received: from ijarvine-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.245.221]) by orviesa009-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Sep 2026 02:33:42 -0700 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Thu, 10 Sep 2026 12:33:38 +0300 (EEST) To: Andy Shevchenko cc: zl020895 , longzhao@ambarella.com, Arnd Bergmann , Krzysztof Kozlowski , Alexandre Belloni , soc@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Rob Herring , Krzysztof Kozlowski , Conor Dooley , Michael Turquette , Stephen Boyd , Linus Walleij , Bartosz Golaszewski , Greg Kroah-Hartman , Jiri Slaby , Catalin Marinas , Will Deacon , Lee Jones , mfd@lists.linux.dev, devicetree@vger.kernel.org, linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org, linux-serial , LKML Subject: Re: Re: [PATCH v6 11/13] serial: 8250_dw: add Ambarella CV75 quirks In-Reply-To: Message-ID: References: <20260904-cv75-v5-v6-0-e918514cb3b1@ambarella.com> <20260904-cv75-v5-v6-11-e918514cb3b1@ambarella.com> <122573f8.8232.1a08a9765fc.Coremail.zl020895@163.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII On Thu, 10 Sep 2026, Andy Shevchenko wrote: > On Thu, Sep 10, 2026 at 05:12:52PM +0800, zl020895 wrote: > > > > Wondering if we should undo this in the port's .shutdown() callback. > > I saw the shutdown path already covers it: dw8250_shutdown() calls > > serial8250_do_shutdown(), which does > > up->ier = 0; > > serial_port_out(port, UART_IER, 0); > > so both the IER shadow and hardware IER are cleared, including ETOI. > > Depending on the answer to Ilpo the enabling may need an updated comment > summarising the above. I'd prefer removing the entire "Force them ..." sentence, it feels really basic detail about how ->ier works. I believe that would resolve your concern if relates to what shutdown does for the flag (clears it while the comment as is says nothing is supposed to clear it). > > At 2026-09-10 16:33:14, "Andy Shevchenko" wrote: > > >On Fri, Sep 04, 2026 at 02:38:18PM +0800, Long Zhao via B4 Relay wrote: > > ... > > > >> + /* > > >> + * Ambarella keeps variant IER bits (e.g. ETOI) set for correct RX > > >> + * timeout behaviour. Force them into the 8250 IER shadow so later > > >> + * generic IER updates do not clear them. > > >> + */ > > > > > >Wondering if we should undo this in the port's .shutdown() callback. > > -- i.