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

From: Baolin Wang
Date: Thu Nov 19 2015 - 01:48:43 EST


>
>> +{
>> + 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.



--
Baolin.wang
Best Regards
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/