From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964784AbaFIJRp (ORCPT ); Mon, 9 Jun 2014 05:17:45 -0400 Received: from ip4-83-240-18-248.cust.nbox.cz ([83.240.18.248]:58396 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754832AbaFIIvY (ORCPT ); Mon, 9 Jun 2014 04:51:24 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Loic Poulain , Jiri Slaby Subject: [PATCH 3.12 023/146] 8250_core: Fix unwanted TX chars write Date: Mon, 9 Jun 2014 10:49:18 +0200 Message-Id: <9ebff4b62caaf11ad6a701f8c4905411410b7728.1402303820.git.jslaby@suse.cz> X-Mailer: git-send-email 1.9.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Loic Poulain 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit b08c9c317e3f7764a91d522cd031639ba42b98cc upstream. On transmit-hold-register empty, serial8250_tx_chars should be called only if we don't use DMA. DMA has its own tx cycle. Signed-off-by: Loic Poulain Reviewed-by: Heikki Krogerus Signed-off-by: Jiri Slaby --- drivers/tty/serial/8250/8250_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index aa6db8f4ee18..bf9d2ac9c9ed 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -1520,7 +1520,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir) status = serial8250_rx_chars(up, status); } serial8250_modem_status(up); - if (status & UART_LSR_THRE) + if (!up->dma && (status & UART_LSR_THRE)) serial8250_tx_chars(up); spin_unlock_irqrestore(&port->lock, flags); -- 1.9.3