From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793255013; b=iQ1KCdKrGIJFFjl7Ww48Co3r8uLNXKojDFMBCu0PssC5Zuxlmct+obOguYuir4fMmEjc 1GmTKuEhPMX+qGd1ZExYw9E1ZXTRpIguX0909VEgujNOFYnmmW7Ua0dZK3iCnzgWFqZ6n f0VDgyX6hAMdPsKnDs2T+i2ZNYnEk24ZrnoS4ShYIlliGXS0Rw6pioTn5L7o8b943lVsS FSFFQMjXQYyCovQ5nhhgItnKAD+TJpEVmGrv3GM6xEktlY5x7lxYpU7dyYRVN93ZzB4Mf GGegf9faUQxaI6HXqrkF0yu95867asSUocKETDZPtU0bByXXMl8crO75Ctt1412EyJw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793255013; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=ekm5UlrcMERWb+Z9yJF3NqZM3X+Bb1WsVBzJNPZWKXY=; b=QVRUs1QkU+t50c3zLckeaU5/ZnQGtIyaTUiCoDK37DanuDRwFjrmzYYq4bNAEMKvqtPo G+an6SBj6IqV+gfKWRtjwXjBEY6VxTrQJrhU40ik+/ZTMGb1NgPZhffV1Uq41V98uPtMJ ZpabUoD3mfPlOx3vEAAdUTBcgx/BpJzelwiK0JCKl8gMprn8oz+3gmZ7OnOyQSAAyJpz+ clZqmZkSfw5sd/wBPW1FWpR/9WE1yeNdh/sjWQC5NFZzwZGKC2Xvn5PGnon/s8pPAjxMY 6IH8hFOGXB4HMkgJhgVf31mtlZxPXF8nPELYLvWhgHQbukGQ2KH8aKNwcPbObx152RQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=LOYyDSsR; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7FC9C606A320; Thu, 29 Oct 2026 06:23:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=LOYyDSsR Received: by smtp.kernel.org (Postfix) with ESMTPSA id 745F31F01825; Thu, 29 Oct 2026 06:23:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793255013; bh=ekm5UlrcMERWb+Z9yJF3NqZM3X+Bb1WsVBzJNPZWKXY=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=LOYyDSsRpnvlmtDx9v6fRsl3VelANDTFL1Vn4jrZ8qQWOT0ay476Ud2sS2/k2w6tI 733BBQII9qdc7+38bp97SE0qsTcJamO7TVtBXOp5YbsqmjrU/NB1wQBAXeQlRhlxPv OkAC6LCpc9/kyt7Y6TH0OWRKtlFmpdkZoeEjAhC8= Date: Thu, 29 Oct 2026 07:23:29 +0100 From: Greg KH To: Hungyu Lin Cc: jirislaby@kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tty: n_tty: convert the full VTIME interval to jiffies Message-ID: <2026102957-suitable-gesture-be83@gregkh> References: <20261029002052.54117-1-dennylin0707@gmail.com> X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261029002052.54117-1-dennylin0707@gmail.com> On Thu, Oct 29, 2026 at 12:20:52AM +0000, Hungyu Lin wrote: > VTIME specifies a timeout in tenths of a second, but n_tty_read() divides > HZ by 10 before multiplying by VTIME. For supported HZ values that are > not divisible by 10, this truncates each decisecond and shortens the > requested interval. For example, HZ=128 and VTIME=40 produce 480 ticks > instead of 512 ticks for four seconds. What real system uses HZ=128 ? In other words, is this a real issue at all? thanks, greg k-h