Re: [PATCH] serial: 8250: Do XR17V35X specific wakeup in serial8250_do_startup

Peter Hurley
2015-07-17T13:34:45Z

On 07/16/2015 04:29 AM, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@suse.de>
>
> The XR17V35X UART needs the ECB bit set in its XR_EFR
> register to enable access to IER [7:5], ISR [5:4], FCR[5:4],
> MCR[7:5], and MSR [7:0].
>
> Also reset the IER register to mask interrupts after access
> to all bits of this register has been enabled.
>
> This makes my 8-port XR17V35X working with the in-kernel
> serial driver.

Reviewed-by: Peter Hurley <peter@hurleysoftware.com>

Also, would you please find out what bits are set in the IER
that this fixes and let me know? I don't have this hardware.

Regards,
Peter Hurley

> Cc: Peter Hurley <peter@hurleysoftware.com>
> Cc: Michael Welling <mwelling@ieee.org>
> Cc: Joe Schultz <jschultz@xes-inc.com>
> Signed-off-by: Joerg Roedel <jroedel@suse.de>
> ---
> drivers/tty/serial/8250/8250_core.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
> index 37fff12..4124a91 100644
> --- a/drivers/tty/serial/8250/8250_core.c
> +++ b/drivers/tty/serial/8250/8250_core.c
> @@ -2164,6 +2164,21 @@ int serial8250_do_startup(struct uart_port *port)
> */
> enable_rsa(up);
> #endif
> +
> + if (port->type == PORT_XR17V35X) {
> + /*
> + * First enable access to IER [7:5], ISR [5:4], FCR [5:4],
> + * MCR [7:5] and MSR [7:0]
> + */
> + serial_port_out(port, UART_XR_EFR, UART_EFR_ECB);
> +
> + /*
> + * Make sure all interrups are masked until initialization is
> + * complete and the FIFOs are cleared
> + */
> + serial_port_out(port, UART_IER, 0);
> + }
> +
> /*
> * Clear the FIFO buffers and disable them.
> * (they will be reenabled in set_termios())
>