Re: [PATCH] usb: gadget: Add the console support for usb-to-serial port

[Baolin Wang]

On 19 November 2015 at 17:36, Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> wrote:
> On 11/19/2015 01:48 AM, Baolin Wang wrote:
>>>
>>>> +{
>>>> +     struct gscons_info *info = gserial_cons.data;
>>>> +     int port_num = gserial_cons.index;
>>>> +     struct usb_request *req;
>>>> +     struct gs_port *port;
>>>> +     struct usb_ep *ep;
>>>> +
>>>> +     if (port_num >= MAX_U_SERIAL_PORTS || port_num < 0) {
>>>> +             pr_err("%s: port num [%d] exceeds the range.\n",
>>>> +                    __func__, port_num);
>>>> +             return -ENXIO;
>>>> +     }
>>>> +
>>>> +     port = ports[port_num].port;
>>>> +     if (!port) {
>>>> +             pr_err("%s: serial line [%d] not allocated.\n",
>>>> +                    __func__, port_num);
>>>> +             return -ENODEV;
>>>> +     }
>>>> +
>>>> +     if (!port->port_usb) {
>>>> +             pr_err("%s: no port usb.\n", __func__);
>>>> +             return -ENODEV;
>>>> +     }
>>>> +
>>>> +     ep = port->port_usb->in;
>>>> +     if (!ep) {
>>>> +             pr_err("%s: no usb endpoint.\n", __func__);
>>>> +             return -ENXIO;
>>>> +     }
>>>
>>> Looking at the caller, gserial_connect(), none of the error
>>> conditions above look possible.
>>>
>>
>> I re-look the code and do some tests, I found the checking is
>> necessary. Cause we get the port number from the console->index, if
>> the cmdline is not set the ttyGS0 as the console, the console->index
>> will be -1 that is a wrong value. Also the serial.c file will create 1
>> usb-to-seial port as default (default n_ports = 1), so we need to
>> check the port and the endpoint of the port. So I think here checking
>> is necessary and I have tested it.
>
> static void gs_console_connect(int port_num)
> {
>         .
>         .
>         if (port_num != gserial_cons.index)
>                 return;
>         .

OK. Thanks.

>         .
>
>
> @@ -1219,6 +1453,7 @@ int gserial_connect(struct gserial *gser, u8 port_num)
>                         gser->disconnect(gser);
>         }
>
> +       status = gs_console_connect(port_num);
>         spin_unlock_irqrestore(&port->port_lock, flags);
>
>         return status;
>
>
>
>
>
>
>



-- 
Baolin.wang
Best Regards
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