From patchwork Tue May 3 08:08:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Slaby X-Patchwork-Id: 569250 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D47A8C433FE for ; Tue, 3 May 2022 08:08:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232613AbiECILr (ORCPT ); Tue, 3 May 2022 04:11:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46432 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231615AbiECILm (ORCPT ); Tue, 3 May 2022 04:11:42 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE86020F5A; Tue, 3 May 2022 01:08:10 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id AA8B71F38D; Tue, 3 May 2022 08:08:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1651565289; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oST/6quGVTIG/7AvfcWNH38FZA1053Lg8E80M28hIlc=; b=H4xE8wA5fckN+Z4Je/Ts5TWK5x0Uz8u2ZtsbUjkdnIsdPTEoS2rb3XyqaaQ3NNMm0seFjs gFvLO+ko5yV89qhlCKe67iXUq0vHg/YEwpBbT1K4XfHawI0K4i3evBT0pAxNz79rwkQbh3 rooj+gisWI4p5shVnL5+zdtT4QEQeog= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1651565289; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oST/6quGVTIG/7AvfcWNH38FZA1053Lg8E80M28hIlc=; b=OUh3Dw3uztirtLxjjR2TiRQy1JFxB/x5riKuW6coGs3afgkOccgukgFNpjPpuafpPW95gC 2g9TmBdAHY777MAQ== Received: from localhost.localdomain (unknown [10.100.208.98]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 79BF72C142; Tue, 3 May 2022 08:08:09 +0000 (UTC) From: Jiri Slaby To: gregkh@linuxfoundation.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Jiri Slaby , stable@vger.kernel.org Subject: [PATCH 2/7] serial: pch: don't overwrite xmit->buf[0] by x_char Date: Tue, 3 May 2022 10:08:03 +0200 Message-Id: <20220503080808.28332-1-jslaby@suse.cz> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220503080613.27601-1-jslaby@suse.cz> References: <20220503080613.27601-1-jslaby@suse.cz> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org When x_char is to be sent, the TX path overwrites whatever is in the circular buffer at offset 0 with x_char and sends it using pch_uart_hal_write(). I don't understand how this was supposed to work if xmit->buf[0] already contained some character. It must have been lost. Remove this whole pop_tx_x() concept and do the work directly in the callers. (Without printing anything using dev_dbg().) Cc: Fixes: 3c6a483275f4 (Serial: EG20T: add PCH_UART driver) Signed-off-by: Jiri Slaby --- drivers/tty/serial/pch_uart.c | 27 +++++++-------------------- 1 file changed, 7 insertions(+), 20 deletions(-) diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c index f872613a5e83..6cb631487383 100644 --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -624,22 +624,6 @@ static int push_rx(struct eg20t_port *priv, const unsigned char *buf, return 0; } -static int pop_tx_x(struct eg20t_port *priv, unsigned char *buf) -{ - int ret = 0; - struct uart_port *port = &priv->port; - - if (port->x_char) { - dev_dbg(priv->port.dev, "%s:X character send %02x (%lu)\n", - __func__, port->x_char, jiffies); - buf[0] = port->x_char; - port->x_char = 0; - ret = 1; - } - - return ret; -} - static int dma_push_rx(struct eg20t_port *priv, int size) { int room; @@ -889,9 +873,10 @@ static unsigned int handle_tx(struct eg20t_port *priv) fifo_size = max(priv->fifo_size, 1); tx_empty = 1; - if (pop_tx_x(priv, xmit->buf)) { - pch_uart_hal_write(priv, xmit->buf, 1); + if (port->x_char) { + pch_uart_hal_write(priv, &port->x_char, 1); port->icount.tx++; + port->x_char = 0; tx_empty = 0; fifo_size--; } @@ -948,9 +933,11 @@ static unsigned int dma_handle_tx(struct eg20t_port *priv) } fifo_size = max(priv->fifo_size, 1); - if (pop_tx_x(priv, xmit->buf)) { - pch_uart_hal_write(priv, xmit->buf, 1); + + if (port->x_char) { + pch_uart_hal_write(priv, &port->x_char, 1); port->icount.tx++; + port->x_char = 0; fifo_size--; }