MPC52xx_uart low_latency

Maxwell MacLean mmaclean at
Sat Nov 17 05:05:52 EST 2012

Hello fellow PPC developers.

My name is Max MacLean, a new subscriber to this list. Thanks for taking my call.
Since I cannot find a way to easily search the archives, I'll ask directly.

Is anyone working on or aware of a patch the MPC52xx_uart driver to provide a 'low_latency' option.

I want to be able to do this (in c++)

struct serial_struct ss;
if(ioctl(m_iSerial, TIOCGSERIAL, &ss))
  ss.flags |= ASYNC_LOW_LATENCY;
  ioctl(m_iSerial, TIOCSSERIAL, &ss))

or  from command line  type  setserial /dev/ttyPSC1 low_latency

I am trying to get data from my fifo into Linux faster. I am currently seeing a 3-8 msec latency
between characters read in the uart and arrival at the tty. It seems like it's a problem that
has been solved on other platforms

best regards,

Maxwell MacLean | Senior Firmware Engineer
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the Linuxppc-dev mailing list