Re: [PATCH] tty: serial: 8250: remove U6715 16550A auto-detection

From: Greg Kroah-Hartman
Date: Wed Mar 20 2013 - 13:20:12 EST


On Tue, Mar 19, 2013 at 08:50:09PM +0100, Philippe Langlais wrote:
> The auto-detection based on 64 bytes fifo size causes troubles
> for the identification of the MultiTechZPX Modems (pci 11c1:0480).
> They loose the ability to do hardware flow control
> (specifically CTS is never set).
>
> Signed-off-by: Philippe Langlais <philippe.langlais@xxxxxx>
> ---
> drivers/tty/serial/8250/8250.c | 9 ---------
> 1 file changed, 9 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c
> index cf6a538..3255014 100644
> --- a/drivers/tty/serial/8250/8250.c
> +++ b/drivers/tty/serial/8250/8250.c
> @@ -1026,15 +1026,6 @@ static void autoconfig_16550a(struct uart_8250_port *up)
>
> return;
> }
> -
> - /*
> - * We distinguish between 16550A and U6 16550A by counting
> - * how many bytes are in the FIFO.
> - */
> - if (up->port.type == PORT_16550A && size_fifo(up) == 64) {
> - up->port.type = PORT_U6_16550A;
> - up->capabilities |= UART_CAP_AFE;
> - }

So you just broke this functionality for all of the other devices it
does work properly for? That's not nice, and not acceptable.

Please fix this properly.

greg k-h
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