From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753840Ab0JVSdd (ORCPT ); Fri, 22 Oct 2010 14:33:33 -0400 Received: from kroah.org ([198.145.64.141]:37723 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758826Ab0JVSYp (ORCPT ); Fri, 22 Oct 2010 14:24:45 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Volker Ernst , Daniel Mack , Andy Green , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Greg Kroah-Hartman Subject: [PATCH 46/49] serial/imx: check that the buffer is non-empty before sending it out Date: Fri, 22 Oct 2010 11:21:25 -0700 Message-Id: <1287771688-14805-46-git-send-email-gregkh@suse.de> X-Mailer: git-send-email 1.7.1 In-Reply-To: <20101022175112.GC13489@kroah.com> References: <20101022175112.GC13489@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Volker Ernst The .start_tx callback (imx_start_tx here) isn't only called when the buffer is non-empty. E.g. after resume or when handshaking is enabled and the other side starts to signal being ready. So check for an empty puffer already before sending the first character. This prevents sending out stale (or uninitialised) data. Signed-off-by: Volker Ernst Signed-off-by: Daniel Mack Cc: Andy Green [ukl: reword commit log, put check in while condition] Signed-off-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman --- drivers/serial/imx.c | 5 ++--- 1 files changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/serial/imx.c b/drivers/serial/imx.c index 66ecc7a..dfcf4b1 100644 --- a/drivers/serial/imx.c +++ b/drivers/serial/imx.c @@ -327,14 +327,13 @@ static inline void imx_transmit_buffer(struct imx_port *sport) { struct circ_buf *xmit = &sport->port.state->xmit; - while (!(readl(sport->port.membase + UTS) & UTS_TXFULL)) { + while (!uart_circ_empty(xmit) && + !(readl(sport->port.membase + UTS) & UTS_TXFULL)) { /* send xmit->buf[xmit->tail] * out the port here */ writel(xmit->buf[xmit->tail], sport->port.membase + URTX0); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); sport->port.icount.tx++; - if (uart_circ_empty(xmit)) - break; } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) -- 1.7.2