Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761699AbbKVDBM (ORCPT ); Sat, 21 Nov 2015 22:01:12 -0500 Received: from mail-cys01nam02on0064.outbound.protection.outlook.com ([104.47.37.64]:33174 "EHLO NAM02-CY1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752696AbbKVC61 (ORCPT ); Sat, 21 Nov 2015 21:58:27 -0500 Authentication-Results: spf=pass (sender IP is 149.199.60.100) smtp.mailfrom=xilinx.com; hurleysoftware.com; dkim=none (message not signed) header.d=none;hurleysoftware.com; dmarc=bestguesspass action=none header.from=xilinx.com; From: Soren Brinkmann To: Greg Kroah-Hartman , Jiri Slaby CC: Michal Simek , , , , "Peter Hurley" , Soren Brinkmann Subject: [PATCH LINUX v3 03/10] tty: xuartps: Don't consider circular buffer when enabling transmitter Date: Sat, 21 Nov 2015 18:59:25 -0800 Message-ID: <1448161172-19717-4-git-send-email-soren.brinkmann@xilinx.com> X-Mailer: git-send-email 2.6.3.3.g9bb996a In-Reply-To: <1448161172-19717-1-git-send-email-soren.brinkmann@xilinx.com> References: <1448161172-19717-1-git-send-email-soren.brinkmann@xilinx.com> X-RCIS-Action: ALLOW X-TM-AS-Product-Ver: IMSS-7.1.0.1224-8.0.0.1202-21954.006 X-TM-AS-User-Approved-Sender: Yes;Yes X-EOPAttributedMessage: 0 X-Forefront-Antispam-Report: CIP:149.199.60.100;CTRY:US;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10009020)(6009001)(2980300002)(438002)(199003)(189002)(50226001)(5001920100001)(50986999)(106466001)(76506005)(57986006)(63266004)(76176999)(6806005)(5001770100001)(107886002)(87936001)(5001960100002)(586003)(92566002)(189998001)(36386004)(229853001)(36756003)(19580405001)(50466002)(48376002)(19580395003)(81156007)(86362001)(77096005)(2950100001)(33646002)(4001430100002)(5008740100001)(47776003)(11100500001)(5003940100001)(5007970100001)(107986001)(217873001)(5001870100001);DIR:OUT;SFP:1101;SCL:1;SRVR:SN1NAM02HT143;H:xsj-pvapsmtpgw02;FPR:;SPF:Pass;PTR:unknown-60-100.xilinx.com,xapps1.xilinx.com;A:1;MX:1;LANG:en; MIME-Version: 1.0 Content-Type: text/plain X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:(8251501001);SRVR:SN1NAM02HT143; X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:(192813158149592); X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(601004)(2401047)(520078)(8121501046)(5005006)(3002001)(10201501046);SRVR:SN1NAM02HT143;BCL:0;PCL:0;RULEID:;SRVR:SN1NAM02HT143; X-Forefront-PRVS: 076804FE30 X-OriginatorOrg: xilinx.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Nov 2015 02:58:24.6860 (UTC) X-MS-Exchange-CrossTenant-Id: 657af505-d5df-48d0-8300-c31994686c5c X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=657af505-d5df-48d0-8300-c31994686c5c;Ip=[149.199.60.100];Helo=[xsj-pvapsmtpgw02] X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN1NAM02HT143 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1690 Lines: 46 Restarting the transmitter even if the circ buffer is empty may be necessary to push out remaining data when the port is restarted after being stopped. Cc: Peter Hurley Signed-off-by: Soren Brinkmann --- v3: - changed this patch to not always enable the transmitter, but keep the check for uart_tx_stopped() in place, as suggested by Peter, whose explanation I also stole for the new commit message (thx) --- drivers/tty/serial/xilinx_uartps.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 2c98c357d9a0..6a7cd4e057ae 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -512,7 +512,7 @@ static void cdns_uart_start_tx(struct uart_port *port) { unsigned int status, numbytes = port->fifosize; - if (uart_circ_empty(&port->state->xmit) || uart_tx_stopped(port)) + if (uart_tx_stopped(port)) return; /* @@ -524,6 +524,9 @@ static void cdns_uart_start_tx(struct uart_port *port) status |= CDNS_UART_CR_TX_EN; writel(status, port->membase + CDNS_UART_CR_OFFSET); + if (uart_circ_empty(&port->state->xmit)) + return; + while (numbytes-- && ((readl(port->membase + CDNS_UART_SR_OFFSET) & CDNS_UART_SR_TXFULL)) != CDNS_UART_SR_TXFULL) { /* Break if no more data available in the UART buffer */ -- 2.6.3.3.g9bb996a -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/