Re: [PATCH 3/3] USB : serial : pl2303 wake up after dcd status check.

From: Johan Hovold
Date: Fri Sep 13 2013 - 12:24:08 EST


On Fri, Sep 13, 2013 at 05:35:13PM +0200, Paul Chavent wrote:
> Seems to be done this way in other drivers (ch341, 8250, ...).
> And get tty reference only if dcd_change need to be called.

This is fine. I have a patch here doing the same two changes as part of
a larger clean-up of the pl2303 interrupt handling (which in turn is
part of the MSR-refactoring I mentioned). I could rebase on top of this,
unless you care to wait another week. :)

Thanks,
Johan

> Signed-off-by: Paul Chavent <paul.chavent@xxxxxxxx>
> ---
> drivers/usb/serial/pl2303.c | 17 +++++++++--------
> 1 file changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
> index e7a84f0..8b81188 100644
> --- a/drivers/usb/serial/pl2303.c
> +++ b/drivers/usb/serial/pl2303.c
> @@ -854,15 +854,16 @@ static void pl2303_update_line_status(struct usb_serial_port *port,
> spin_unlock_irqrestore(&priv->lock, flags);
> if (priv->line_status & UART_BREAK_ERROR)
> usb_serial_handle_break(port);
> - wake_up_interruptible(&port->port.delta_msr_wait);
>
> - tty = tty_port_tty_get(&port->port);
> - if (!tty)
> - return;
> - if ((priv->line_status ^ prev_line_status) & UART_DCD)
> - usb_serial_handle_dcd_change(port, tty,
> - priv->line_status & UART_DCD);
> - tty_kref_put(tty);
> + if ((priv->line_status ^ prev_line_status) & UART_DCD) {
> + tty = tty_port_tty_get(&port->port);
> + if (tty)
> + usb_serial_handle_dcd_change(port, tty,
> + priv->line_status & UART_DCD);
> + tty_kref_put(tty);
> + }
> +
> + wake_up_interruptible(&port->port.delta_msr_wait);
> }
>
> static void pl2303_read_int_callback(struct urb *urb)
> --
> 1.7.12.1
>
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