On Sat, Jun 23, 2012 at 09:19:40PM +0200, Stefan Wahren wrote:

Hello,

i'm using Linux 2.6.35 at ARM and i experience the following issue
with the mxs-auart (App UART). If i transmit and receive data over
the serial port (using mxs-auart), all the interrupt counter (RX,
TX, frame, parity, break) accessed from user space (ioctl with
TIOCGICOUNT or /proc/tty/driver/auart) are zero.

Here is the scenario to reproduce the problem:

1. echoing some characters to the uart device
2. fetch the statistics from proc-Filesystem

Expected results: transmit counter greater than zero

Observed results: transmit counter is always zero

The same szenario on the mxs-duart (Debug UART) doesn't show this problem.

Is this a bug in mxs-auart or just not implemented?

We disabled the transmit counter from being displayed a while ago for
security reasons, perhaps that is what you are seeing?

Also, you do realize just how old 2.6.35 really is, right?

thanks,

greg k-h