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 A07703D1AAA; 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=t/aTBZyNBlohyRQMWz5w79I42D/y2TPdEZpHQizk2lMWvsXn+T/fSDsAyJJEamDkyZhBzYr5aHRG1qYuMKM0aUl34hbH96ibo/jpzjqbzTGZ6uhKgXeeIKlXvUij5MYaydjEPQdPSbqRZsyYX7iMW59m89WNFC58wNr1HxTB+fg= 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=j0Afn0Le; 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="j0Afn0Le" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1789032832; x=1820568832; h=from:date:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=FjcDcqvU0235HfXhQqh3BNVRPpVFE3oJFo7uUnHGA88=; b=j0Afn0Lej0ydhpIAQ+NGGwmQv9OO/GXEe9LiG5Hf9MONOtGPXjrBp/Ul AR+ILa2OtVrPWgMDZbF1eaBlJIcFSfQ40Xang+3kVVrwJpyzqgN6K2/Wu zMTv7MMIT7AbD7wa0jHJZFdfoAhbiRHtuzLYSU4+Lr5EaDBPsIKXJrBIN aGMDCrx4LP1VjOUgrPnC/7t/Y/yijND4hbKDW+RCbzcVnvOkhtaDA3v1+ gueI5GoRp8Co+8I5yh95b/RhAIAqjni6XdZKZg3maExzZUKyu7TFp6589 m3HrsnZX+8EBTHoMNOJUGMEyJci1vO2TiIuMg5PsrsTgB4jKSR9gc1x1f Q==; X-CSE-ConnectionGUID: W7+EuS1oTR2TZc8f6YpZrQ== X-CSE-MsgGUID: vUmkur0qReWdVXBsJmk9Cg== X-IronPort-AV: E=McAfee;i="6800,10657,11900"; a="89509916" X-IronPort-AV: E=Sophos;i="6.27,95,1787036400"; d="scan'208";a="89509916" 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: soc@lists.linux.dev 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.