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

Philippe LANGLAIS
2013-03-21T08:37:21Z

On 03/20/2013 06:21 PM, Greg Kroah-Hartman wrote:
> 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@st.com>
>> ---
>> 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.
Yes, I know, but as U6715 & U6XXX kernel maintainer there is no risk to
do that,
kernel for such platforms are not managed in mainstream, there are more
risks
to keep these lines for other platforms.
>
> Please fix this properly.
I don't know how to distinguish MultiTechZPX Modems, so I rather to
remove these lines.
>
> greg k-h
Philippe