From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) (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 63AF317DFFE; Fri, 20 Sep 2024 15:58:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726847910; cv=none; b=UeLm/0ECzYaz9MYcuFyFFIgcfyHeB7gMaRsLbGmLu7SI2GCVz+4VKNLXPZdzYBsqP9EbZ5GUKbR2UJfbCiATfZ8V8EtTvN1SFrkMImemiFn5ZNPIhz6C4VFGcatCdN5idngnH1Vu2clPmh9bsf4yD9SwR49CGZa5A/x0wRLfQtM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726847910; c=relaxed/simple; bh=XNfFFrRVo8a4wL2UR3VbWZtjgrhwmDIpuPmCd0POBCI=; h=From:Date:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=pjB+Jj8KWfzoQE7SHoKX5uxHQJ0RLAc4Gek9D6GmAXiNVSqImSPPtww7apdkaXBu54EHRbsJqWjqXu32WAh/yMIVWYVzjLMPhw54poQ1E/FcV5j1RWPzMA393LA1752Ku2sVw8zgoK4aqPHj+vDAf0Q9Av22QovDo9n44ItJFb4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=SEVnVaUC; arc=none smtp.client-ip=198.175.65.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none 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="SEVnVaUC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1726847910; x=1758383910; h=from:date:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=XNfFFrRVo8a4wL2UR3VbWZtjgrhwmDIpuPmCd0POBCI=; b=SEVnVaUCMGV+Kol5lmhpldq3L11PeVo6fBzvxj46pbuyhm6g5J5wbJdo 0mURDAZBYyEnUAhNbtocnsFR1FhtJ7fN5dC27XgxQB2CN3+jHwlbKYymg 7Wmf8LE4E8zIZUb+hUbARr2DuThijLn/ATapaL26dCXoXAx+9ByixThCT KCJaN8JWVJc/iWsTAvVsR+uDCGZVn7gBOUsktQRrI+f8RKK5dRNwnF2ee x4knmDJxRra/hMxNx5TjP49aGN3cS2UszATrR0XkBL6roqr/LBkI+IkXT 6fvt28kOukSiW9d6Ho3xLcRchmMkDTNsgw2qHCHmaFwYvOcaIU7i3fvWr g==; X-CSE-ConnectionGUID: aGx7cwjqQcC2Q97OVoxLkA== X-CSE-MsgGUID: 2IztmSfHTS+ncdHZfWmbdg== X-IronPort-AV: E=McAfee;i="6700,10204,11201"; a="36993372" X-IronPort-AV: E=Sophos;i="6.10,244,1719903600"; d="scan'208";a="36993372" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Sep 2024 08:58:29 -0700 X-CSE-ConnectionGUID: yXk6fyQHQN2yIOKlPR89xA== X-CSE-MsgGUID: eZG4rdVpRyKxvYFXLfNMrg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,244,1719903600"; d="scan'208";a="70787342" Received: from ijarvine-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.245.61]) by orviesa007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Sep 2024 08:58:24 -0700 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Fri, 20 Sep 2024 18:58:21 +0300 (EEST) To: Jiri Slaby , LiangCheng Wang cc: shawnguo@kernel.org, s.hauer@pengutronix.de, Greg Kroah-Hartman , kernel@pengutronix.de, festevam@gmail.com, u.kleine-koenig@pengutronix.de, cniedermaier@dh-electronics.com, l.sanfilippo@kunbus.com, linux@rasmusvillemoes.dk, stefan.eichenberger@toradex.com, tglx@linutronix.de, rickaran@axis.com, LKML , linux-serial , imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 1/1] drivers: tty: imx: fix flags of rs485 not work properly In-Reply-To: <7a31001d-da37-4deb-a366-084a4027bcd2@suse.cz> Message-ID: References: <20240906021905.197891-1-zaq14760@gmail.com> <7a31001d-da37-4deb-a366-084a4027bcd2@suse.cz> 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 Fri, 6 Sep 2024, Jiri Slaby wrote: > It seems gmail refuses to send this to zaq14760@gmail.com (the author). > > On 06. 09. 24, 4:19, LiangCheng Wang wrote: > > The rs485.flags are lost in functions such as imx_uart_stop_tx(), > > causing the function of RS485 to be invalid when using the > > serial port as the RS485 port. Use a variable to store the state to > > avoid this issue. > > AFAICT, this feels rather wrong. Any rs485 experts around? It is wrong. The patch makes no sense at all and prevents reconfiguring/setting rs485 from userspace. > At minimum, how are the flags "lost" and why this does not matter to other > drivers? Perhaps some userspace program is altering rs485 settings, definitely nothing in imx_uart_stop_tx() writes to it. I'm skeptical it would be a problem in the kernel, especially given the patch that is supposed to "avoid the issue" (whatever the issue is). > > --- a/drivers/tty/serial/imx.c > > +++ b/drivers/tty/serial/imx.c > > @@ -209,7 +209,7 @@ struct imx_port { > > const struct imx_uart_data *devdata; > > struct mctrl_gpios *gpios; > > - > > + int flags; > > Definitely not int for flags. Driver is not supposed to duplicate the rs485 flags at all. -- i.