[Qemu-devel] Re: more about serial ports: do they even work?

["David S. Ahern" <daahern@cisco.com>]

Michael Tokarev wrote:
> David S. Ahern wrote:
>> I don't recall seeing a followup to this post.
>>
>> To put Michael's second suggestion into patch form, the following fixes
>> the problem for me:
>>
>> --- kvm-81.orig/qemu/qemu-char.c        2008-12-14 06:16:27.000000000 -0700
>> +++ kvm-81/qemu/qemu-char.c     2009-02-02 14:12:20.000000000 -0700
>> @@ -1078,20 +1078,21 @@
>>              if (sarg | TIOCM_DTR)
>>                  *targ |= CHR_TIOCM_DTR;
>>              if (sarg | TIOCM_RTS)
>>                  *targ |= CHR_TIOCM_RTS;
>>          }
>>          break;
>>      case CHR_IOCTL_SERIAL_SET_TIOCM:
>>          {
>>              int sarg = *(int *)arg;
>>              int targ = 0;
>> +            ioctl(s->fd_in, TIOCMGET, &targ);
> 
> here, one more operation is necessary:
>                targ &= ~(TIOCM_DTR|TIOCM_RTS);
> 


Interesting. that change was not needed to fix my problem.

david


>>              if (sarg | CHR_TIOCM_DTR)
>>                  targ |= TIOCM_DTR;
>>              if (sarg | CHR_TIOCM_RTS)
>>                  targ |= TIOCM_RTS;
>>              ioctl(s->fd_in, TIOCMSET, &targ);
>>          }
>>          break;
>>      default:
>>          return -ENOTSUP;
>>      }
>>
>> Is this approach palatable to folks?
>>
>> david
> 
> /mjt