[PATH RESEND v2 05/10] tty: xuartps: Improve startup function
From: Soren Brinkmann <hidden>
Date: 2015-11-19 20:16:12
Also in:
linux-serial, lkml
Subsystem:
the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
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 <redacted> --- 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 b7fc30639292..167e0f4bcf7a 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c@@ -755,6 +755,7 @@ 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,
@@ -762,6 +763,8 @@ 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);
@@ -772,15 +775,14 @@ 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.
@@ -811,6 +813,8 @@ 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; }
--
2.6.3.3.g9bb996a