serial: PL011: move interrupt clearing

[pandora-kernel.git] / drivers / tty / serial / amba-pl011.c

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 00233af..6da8cf8 100644 (file)
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1380,6 +1380,10 @@ static int pl011_startup(struct uart_port *port)
 
        uap->port.uartclk = clk_get_rate(uap->clk);
 
+       /* Clear pending error and receive interrupts */
+       writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS |
+              UART011_RTIS | UART011_RXIS, uap->port.membase + UART011_ICR);
+
        /*
         * Allocate the IRQ
         */
@@ -1414,10 +1418,6 @@ static int pl011_startup(struct uart_port *port)
        cr = UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE;
        writew(cr, uap->port.membase + UART011_CR);
 
-       /* Clear pending error interrupts */
-       writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS,
-              uap->port.membase + UART011_ICR);
-
        /*
         * initialise the old status of the modem signals
         */
@@ -1432,6 +1432,9 @@ static int pl011_startup(struct uart_port *port)
         * as well.
         */
        spin_lock_irq(&uap->port.lock);
+       /* Clear out any spuriously appearing RX interrupts */
+        writew(UART011_RTIS | UART011_RXIS,
+               uap->port.membase + UART011_ICR);
        uap->im = UART011_RTIM;
        if (!pl011_dma_rx_running(uap))
                uap->im |= UART011_RXIM;
@@ -1740,9 +1743,19 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
 {
        struct uart_amba_port *uap = amba_ports[co->index];
        unsigned int status, old_cr, new_cr;
+       unsigned long flags;
+       int locked = 1;
 
        clk_enable(uap->clk);
 
+       local_irq_save(flags);
+       if (uap->port.sysrq)
+               locked = 0;
+       else if (oops_in_progress)
+               locked = spin_trylock(&uap->port.lock);
+       else
+               spin_lock(&uap->port.lock);
+
        /*
         *      First save the CR then disable the interrupts
         */
@@ -1762,6 +1775,10 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
        } while (status & UART01x_FR_BUSY);
        writew(old_cr, uap->port.membase + UART011_CR);
 
+       if (locked)
+               spin_unlock(&uap->port.lock);
+       local_irq_restore(flags);
+
        clk_disable(uap->clk);
 }
 
@@ -1918,6 +1935,10 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
        uap->port.line = i;
        pl011_dma_probe(uap);
 
+       /* Ensure interrupts from this UART are masked and cleared */
+       writew(0, uap->port.membase + UART011_IMSC);
+       writew(0xffff, uap->port.membase + UART011_ICR);
+
        snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev));
 
        amba_ports[i] = uap;