From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFAA5C28E80 for ; Wed, 3 Mar 2021 01:02:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F46664FA6 for ; Wed, 3 Mar 2021 01:02:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343555AbhCCAxG (ORCPT ); Tue, 2 Mar 2021 19:53:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:44180 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1580921AbhCBSW0 (ORCPT ); Tue, 2 Mar 2021 13:22:26 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6CE8560295; Tue, 2 Mar 2021 18:21:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614709304; bh=ISDrXxWHSH+zFovoD5AGTuD09XaOpEusjNmd/Hylyis=; h=Subject:To:From:Date:From; b=sPvRACaVTTwR0D6ZIs/ao45KxTG+TvCsWnptHMFf8nhZXsr6g8P7k98MguFy/EUrp /pmuVhcLpQYYJ8rfO6JE056M6nY/RqgREn1Ypm0lvZiAe78+JG0OgRyWIdpIDf1ydZ dpmZCNXPTx64jJJtVwcLU1TU4xhLdjNXozeBoaqY= Subject: patch "Revert "serial: max310x: rework RX interrupt handling"" added to tty-linus To: shc_work@mail.ru, gregkh@linuxfoundation.org, stable@vger.kernel.org, thomas.petazzoni@bootlin.com From: Date: Tue, 02 Mar 2021 19:21:42 +0100 Message-ID: <1614709302126254@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled Revert "serial: max310x: rework RX interrupt handling" to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From 511a9d5dc2d4d541704d25faf7f6fc2a71a2fd9d Mon Sep 17 00:00:00 2001 From: Alexander Shiyan Date: Wed, 17 Feb 2021 11:06:08 +0300 Subject: Revert "serial: max310x: rework RX interrupt handling" This reverts commit fce3c5c1a2d9cd888f2987662ce17c0c651916b2. FIFO is triggered 4 intervals after receiving a byte, it's good when we don't care about the time of reception, but are only interested in the presence of any activity on the line. Unfortunately, this method is not suitable for all tasks, for example, the RS-485 protocol will not work properly, since the state machine must track the request-response time and after the timeout expires, a decision is made that the device on the line is not responding. Signed-off-by: Alexander Shiyan Link: https://lore.kernel.org/r/20210217080608.31192-1-shc_work@mail.ru Fixes: fce3c5c1a2d9 ("serial: max310x: rework RX interrupt handling") Cc: Thomas Petazzoni Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/max310x.c | 29 +++++------------------------ 1 file changed, 5 insertions(+), 24 deletions(-) diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c index 9795b2e8b0b2..1b61d26bb7af 100644 --- a/drivers/tty/serial/max310x.c +++ b/drivers/tty/serial/max310x.c @@ -1056,9 +1056,9 @@ static int max310x_startup(struct uart_port *port) max310x_port_update(port, MAX310X_MODE1_REG, MAX310X_MODE1_TRNSCVCTRL_BIT, 0); - /* Reset FIFOs */ - max310x_port_write(port, MAX310X_MODE2_REG, - MAX310X_MODE2_FIFORST_BIT); + /* Configure MODE2 register & Reset FIFOs*/ + val = MAX310X_MODE2_RXEMPTINV_BIT | MAX310X_MODE2_FIFORST_BIT; + max310x_port_write(port, MAX310X_MODE2_REG, val); max310x_port_update(port, MAX310X_MODE2_REG, MAX310X_MODE2_FIFORST_BIT, 0); @@ -1086,27 +1086,8 @@ static int max310x_startup(struct uart_port *port) /* Clear IRQ status register */ max310x_port_read(port, MAX310X_IRQSTS_REG); - /* - * Let's ask for an interrupt after a timeout equivalent to - * the receiving time of 4 characters after the last character - * has been received. - */ - max310x_port_write(port, MAX310X_RXTO_REG, 4); - - /* - * Make sure we also get RX interrupts when the RX FIFO is - * filling up quickly, so get an interrupt when half of the RX - * FIFO has been filled in. - */ - max310x_port_write(port, MAX310X_FIFOTRIGLVL_REG, - MAX310X_FIFOTRIGLVL_RX(MAX310X_FIFO_SIZE / 2)); - - /* Enable RX timeout interrupt in LSR */ - max310x_port_write(port, MAX310X_LSR_IRQEN_REG, - MAX310X_LSR_RXTO_BIT); - - /* Enable LSR, RX FIFO trigger, CTS change interrupts */ - val = MAX310X_IRQ_LSR_BIT | MAX310X_IRQ_RXFIFO_BIT | MAX310X_IRQ_TXEMPTY_BIT; + /* Enable RX, TX, CTS change interrupts */ + val = MAX310X_IRQ_RXEMPTY_BIT | MAX310X_IRQ_TXEMPTY_BIT; max310x_port_write(port, MAX310X_IRQEN_REG, val | MAX310X_IRQ_CTS_BIT); return 0; -- 2.30.1