DTR / DTS vs RTS/CTS vs Wine

[Mike McCormack]

Hi Miguel,

You are correct; the Linux kernel does not support DTR/DSR flow control. 
If a windows program requests DTR/DSR flow control in wine, we just 
write a FIXME to stderr and ignore the setting.

Your idea to build a cable that wires the printer's DTR/DSR to the 
computer's RTS/CTS may work, but you may also need some small hacks in 
wine to select RTS/CTS flow control when the program asks for DTR/DSR 
flow control. That won't garantuee that your program works, but it will 
at least be a little better...

I guess the other option is to implement DTR/DSR flow control in the 
Linux kernel... but that may not be easy :)

Mike


List vmn wrote:
> Hi,
> 
> I am testing a serial printer driver that uses DTR/DTS  hardware flow 
> control on wine.
> While testing the driver running winedbg everything worked, not so when 
> I ran the program directly from wine.
> I sent this problem to the printer manufacturer and they put a data 
> scope on the serial line.
> It seems that the DTR/DTS signal was not being caught by the computer 
> and therefore the computer was sending info
> over the serial port when the printer was not ready.
> I read on the net that the linux  kernel does not  implement  DTR/DTS 
> but only RTS/CTS hardware flow control.
> 
> I also read that it is usual for cables to be built that connect the 
> RTS/CTS pins to the DTR/DTS pins therefore tricking the computer and 
> printer [the computer understands RTS/CTS and the printer DTR/DTS ] and 
> getting good results.
> 
> The output of --debugmsg +comm after SetCommState was called was ~IXONN 
> ~IXOFF.
> Can anybody indicate that If I build the correct cable and ask for 
> RTS/CTS with SetCommState , that the serial io will work?
> Any limitation of wine with RTS/CTS?
> 
> Is it correct that windows does not do ANY hardware flow control?
> If so, how can this app work under windows since it only uses standard 
> SetCommState, ReadFile, WriteFile calls...
> 
> Thanks,
> Miguel  Feitosa
> 
>