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Sun, 22 Nov 2015 02:58:23 +0000 Received: from unknown-38-66.xilinx.com ([149.199.38.66]:47179 helo=xsj-pvapsmtp01) by xsj-pvapsmtpgw02 with esmtp (Exim 4.63) (envelope-from ) id 1a0Kr9-0005sQ-33; Sat, 21 Nov 2015 18:58:23 -0800 Received: from [127.0.0.1] (helo=localhost) by xsj-pvapsmtp01 with smtp (Exim 4.63) (envelope-from ) id 1a0Kr8-00059z-UJ; Sat, 21 Nov 2015 18:58:22 -0800 Received: from xsj-pvapsmtp01 (xsj-mail.xilinx.com [149.199.38.66]) by xsj-smtp-dlp1.xlnx.xilinx.com (8.13.8/8.13.1) with ESMTP id tAM2wKxC019345; Sat, 21 Nov 2015 18:58:20 -0800 Received: from [172.19.74.49] (helo=localhost) by xsj-pvapsmtp01 with esmtp (Exim 4.63) (envelope-from ) id 1a0Kr6-00059V-N1; Sat, 21 Nov 2015 18:58:20 -0800 From: Soren Brinkmann To: Greg Kroah-Hartman , Jiri Slaby Subject: [PATCH LINUX v3 05/10] tty: xuartps: Improve startup function Date: Sat, 21 Nov 2015 18:59:27 -0800 Message-ID: <1448161172-19717-6-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; 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SRVR:BL2NAM02HT064; BCL:0; PCL:0; RULEID:; SRVR:BL2NAM02HT064; X-Forefront-PRVS: 076804FE30 X-OriginatorOrg: xilinx.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Nov 2015 02:58:23.8890 (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: BL2NAM02HT064 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20151121_185848_507083_BC56ACBB X-CRM114-Status: GOOD ( 12.87 ) X-Spam-Score: -1.9 (-) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Hurley , Michal Simek , linux-kernel@vger.kernel.org, Soren Brinkmann , linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The startup function is supposed to initialize the UART for receiving. Hence, don't enable the TX part. Also, protect HW accesses with the port lock. Signed-off-by: Soren Brinkmann Reviewed-by: Peter Hurley --- drivers/tty/serial/xilinx_uartps.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index ef114d7a0623..6ffd3bbe3e18 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -758,6 +758,7 @@ static void cdns_uart_set_termios(struct uart_port *port, */ static int cdns_uart_startup(struct uart_port *port) { + unsigned long flags; unsigned int retval = 0, status = 0; retval = request_irq(port->irq, cdns_uart_isr, 0, CDNS_UART_NAME, @@ -765,6 +766,8 @@ static int cdns_uart_startup(struct uart_port *port) if (retval) return retval; + spin_lock_irqsave(&port->lock, flags); + /* Disable the TX and RX */ writel(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS, port->membase + CDNS_UART_CR_OFFSET); @@ -775,15 +778,14 @@ static int cdns_uart_startup(struct uart_port *port) writel(CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST, port->membase + CDNS_UART_CR_OFFSET); - status = readl(port->membase + CDNS_UART_CR_OFFSET); - - /* Clear the RX disable and TX disable bits and then set the TX enable - * bit and RX enable bit to enable the transmitter and receiver. + /* + * Clear the RX disable bit and then set the RX enable bit to enable + * the receiver. */ - writel((status & ~(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS)) - | (CDNS_UART_CR_TX_EN | CDNS_UART_CR_RX_EN | - CDNS_UART_CR_STOPBRK), - port->membase + CDNS_UART_CR_OFFSET); + status = readl(port->membase + CDNS_UART_CR_OFFSET); + status &= CDNS_UART_CR_RX_DIS; + status |= CDNS_UART_CR_RX_EN; + writel(status, port->membase + CDNS_UART_CR_OFFSET); /* Set the Mode Register with normal mode,8 data bits,1 stop bit, * no parity. @@ -814,6 +816,8 @@ static int cdns_uart_startup(struct uart_port *port) CDNS_UART_IXR_RXTRIG | CDNS_UART_IXR_TOUT, port->membase + CDNS_UART_IER_OFFSET); + spin_unlock_irqrestore(&port->lock, flags); + return retval; }