[Ftdi-usb-sio-devel] low_latency flag for ftdi_sio

[Boris Z. <bs_...@ya...>]

Hello,

I have some device that uses ftdi chip
to communicate with host computer. I set
low latency flag in this manner

struct serial_struct serial_info;
ioctl(m_fd, TIOCGSERIAL, &serial_info)  ;
serial_info.flags |= ASYNC_LOW_LATENCY;
ioctl(m_fd, TIOCSSERIAL, &serial_info) ;

setserial reports that low_latency flag is
indeed set, but round-trip time for short commands
is about 15 msec. This device has also regular RS232
input and the same code produces 1.5msec 
roundtrip time for the same commands (ten times
faster !!). Is low_latency flag has no effect on ftdi_sio
driver ? If so how can I improve latency.

Best regards,
Boris Zingerman


 
---------------------------------
Bored stiff? Loosen up...
Download and play hundreds of games for free on Yahoo! Games.