Index: linux-2.6.21.7/drivers/serial/pxa.c =================================================================== --- linux-2.6.21.7.orig/drivers/serial/pxa.c +++ linux-2.6.21.7/drivers/serial/pxa.c @@ -235,15 +235,19 @@ static inline irqreturn_t serial_pxa_irq struct uart_pxa_port *up = dev_id; unsigned int iir, lsr; + serial_out(up, UART_MCR, serial_in(up, UART_MCR) & ~UART_MCR_RTS); // Clear RTS iir = serial_in(up, UART_IIR); if (iir & UART_IIR_NO_INT) - return IRQ_NONE; + { + //printk(KERN_WARNING "serial_pxa_irq: odd -- interrupt triggered, but no interrupt in IIR: %08x\n",iir); + } lsr = serial_in(up, UART_LSR); if (lsr & UART_LSR_DR) receive_chars(up, &lsr); check_modem_status(up); if (lsr & UART_LSR_THRE) transmit_chars(up); + serial_out(up, UART_MCR, serial_in(up, UART_MCR) | UART_MCR_RTS); // Assert RTS return IRQ_HANDLED; }