On Fri, Aug 18, 2006 at 07:18:38PM +0400, Vitaly Wool wrote:
> +/* We've been assigned a range on the "Low-density serial ports" major */
No you haven't. You're re-using the StrongARM sa1100 serial port major/
minor.
> +#define SERIAL_PNX8XXX_MAJOR 204
> +#define MINOR_START 5
...
> +static void
> +pnx8xxx_rx_chars(struct pnx8xxx_port *sport, struct pt_regs *regs)
> +{
> + struct tty_struct *tty = sport->port.info->tty;
> + unsigned int status, ch, flg;
> +
> + status = FIFO_TO_SM(serial_in(sport, PNX8XXX_FIFO)) |
> + ISTAT_TO_SM(serial_in(sport, PNX8XXX_ISTAT));
> + while (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFIFO)) {
> + ch = serial_in(sport, PNX8XXX_FIFO);
> +
> + sport->port.icount.rx++;
> +
> + flg = TTY_NORMAL;
> +
> + /*
> + * note that the error handling code is
> + * out of the main execution path
> + */
> + if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE |
> + PNX8XXX_UART_FIFO_RXPAR)) {
What about overrun status?
> + if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR))
> + sport->port.icount.parity++;
> + else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE))
> + sport->port.icount.frame++;
> + if (status & ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN))
> + sport->port.icount.overrun++;
You're not masking with the status that we want to know about - which
means you're going to be marking characters with parity/frame errors
which should otherwise be ignored. This is important since there's
termios modes to enable parity checking by the port _but_ ignore the
status when it occurs.
> +
> + if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR))
> + flg = TTY_PARITY;
> + else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE))
> + flg = TTY_FRAME;
> +
> +#ifdef SUPPORT_SYSRQ
> + sport->port.sysrq = 0;
> +#endif
> + }
> +
> + if (uart_handle_sysrq_char(&sport->port, ch, regs))
> + goto ignore_char;
> +
> + uart_insert_char(&sport->port, status, UART_LSR_OE, ch, flg);
Does UART_LSR_OE really tie up with one of your flags in "status" meaning
"overrun" ?
When you get an overrun status flag set, is the character you read valid?
If it isn't, you shouldn't use uart_insert_char() since that assumes it
is valid.
> +
> + ignore_char:
> + serial_out(sport, PNX8XXX_LCR, serial_in(sport, PNX8XXX_LCR) |
> + PNX8XXX_UART_LCR_RX_NEXT);
> + status = FIFO_TO_SM(serial_in(sport, PNX8XXX_FIFO)) |
> + ISTAT_TO_SM(serial_in(sport, PNX8XXX_ISTAT));
> + }
> + tty_flip_buffer_push(tty);
> +}
...
> +static irqreturn_t pnx8xxx_int(int irq, void *dev_id, struct pt_regs *regs)
> +{
> + struct pnx8xxx_port *sport = dev_id;
> + unsigned int status;
> +
> + spin_lock(&sport->port.lock);
> + /* Get the interrupts */
> + status = serial_in(sport, PNX8XXX_ISTAT) & serial_in(sport, PNX8XXX_IEN);
> +
> + /* RX Receiver Holding Register Overrun */
> + if (status & PNX8XXX_UART_INT_RXOVRN) {
> + sport->port.icount.overrun++;
> + serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_RXOVRN);
> + }
> +
> + /* RX Frame Error */
> + if (status & PNX8XXX_UART_INT_FRERR) {
> + sport->port.icount.frame++;
> + serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_FRERR);
> + }
> +
> + /* Break signal received */
> + if (status & PNX8XXX_UART_INT_BREAK) {
> + sport->port.icount.brk++;
> + serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_BREAK);
If there's no break handling, you can remove the call to
uart_handle_sysrq_char() in your receive function - it'll never do
anything useful.
> + }
> +
...
> +static void
> +pnx8xxx_set_termios(struct uart_port *port, struct termios *termios,
> + struct termios *old)
> +{
> + struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
> + unsigned long flags;
> + unsigned int lcr_fcr, old_ien, baud, quot;
> + unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
> +
> + /*
> + * We only support CS7 and CS8.
> + */
> + while ((termios->c_cflag & CSIZE) != CS7 &&
> + (termios->c_cflag & CSIZE) != CS8) {
> + termios->c_cflag &= ~CSIZE;
> + termios->c_cflag |= old_csize;
> + old_csize = CS8;
> + }
> +
> + if ((termios->c_cflag & CSIZE) == CS8)
> + lcr_fcr = PNX8XXX_UART_LCR_8BIT;
> + else
> + lcr_fcr = 0;
> +
> + if (termios->c_cflag & CSTOPB)
> + lcr_fcr |= PNX8XXX_UART_LCR_2STOPB;
> + if (termios->c_cflag & PARENB) {
> + lcr_fcr |= PNX8XXX_UART_LCR_PAREN;
> + if (!(termios->c_cflag & PARODD))
> + lcr_fcr |= PNX8XXX_UART_LCR_PAREVN;
> + }
> +
> + /*
> + * Ask the core to calculate the divisor for us.
> + */
> + baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
> + quot = uart_get_divisor(port, baud);
> +
> + spin_lock_irqsave(&sport->port.lock, flags);
> +
> + sport->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
> + if (termios->c_iflag & INPCK)
> + sport->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
> + if (termios->c_iflag & (BRKINT | PARMRK))
> + sport->port.read_status_mask |= UART_LSR_BI;
Doubt this is correct.
> +
> + /*
> + * Characters to ignore
> + */
> + sport->port.ignore_status_mask = 0;
> + if (termios->c_iflag & IGNPAR)
> + sport->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
> + if (termios->c_iflag & IGNBRK) {
> + sport->port.ignore_status_mask |= UART_LSR_BI;
> + /*
> + * If we're ignoring parity and break indicators,
> + * ignore overruns too (for real raw support).
> + */
> + if (termios->c_iflag & IGNPAR)
> + sport->port.ignore_status_mask |= UART_LSR_OE;
> + }
Ditto. In which case you probably don't want serial_reg.h included (you
don't want it in any case - your device is not 8250 compatible and you're
using your own register definitions.)
...
> +static int pnx8xxx_serial_suspend(struct platform_device *pdev, pm_message_t state)
> +{
> + struct pnx8xxx_port *sport = platform_get_drvdata(pdev);
> +
> + uart_suspend_port(&pnx8xxx_reg, &sport->port);
What if uart_suspend_port() wanted to return an error?
> + return 0;
> +}
> +
> +static int pnx8xxx_serial_resume(struct platform_device *pdev)
> +{
> + struct pnx8xxx_port *sport = platform_get_drvdata(pdev);
> +
> + uart_resume_port(&pnx8xxx_reg, &sport->port);
What if uart_resume_port() wanted to return an error?
> +
> + return 0;
> +}
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
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