On Thu, Jul 14, 2016 at 2:14 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, Jul 13, 2016 at 10:59:10AM +0530, Malith Yapa wrote:
>> I think i am.
>>
>> int readDword(int addr) {
>>
>> uint16_t reg[1];// will store read registers values
>>
>> int num = modbus_read_registers(ctx, addr, 1, reg); //16386 = X2
>>
>> usleep(5);
>>
>> if (num != 1) {
>> fprintf(stderr, "Failed(%i) to read: %s\n", num,
>> modbus_strerror(errno));
>> modbus_close(ctx);
>> modbus_free(ctx);
>> sleep(5);
>> int wait = 1;
>> while(initModbus()) {
>> cerr << "Waiting for PLC.. SLEEP[" << wait*20 << "]" << endl;
>> sleep(wait*20);
>> wait++;
>> }
>> }
>>
>> return reg[0];
>> }
>>
>> according to modbus documentation, "The modbus_close() function shall
>> close the connection established with the backend set in the context."
>>
>> Even if not. Shouldn't the minor number's go upto 512 (as Johan
>> pointed out) before giving up?
>
> Yes it should.
>
>> The system is an Olimex A20-micro,
>> Linux version 3.4.90+ (gcc version 4.7.1 (Debian 4.7.1-7) )
>
> Ugh, 3.4 is a very old, and obsolete kernel version. Please get support
> for it from the vendor that is forcing you to use such a thing, as you
> are already paying for it from them.
>
> We can help you out if you can reproduce this on 4.6, have you tried
> that?
>
> thanks,
>
> greg k-h
Looks like sunxi only provides a 3.4 kernel. I lack the expertise to
try to build 4.6 for this board so I'll try reporting it to them.
Thanks,
Malith
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