2.6.33 kernel

Hello All,

I have just compile 2.6.33 kernel using RT patch
2.6.33-Test #16 PREEMPT RT Mon Dec 19 14:49:30 IST 2011 armv4tl unknown

and successfully ported to board, but when i type any command such as 'ls'
it respond too slow, do i need to compile whole file system using rtapi ?
or just rt kernel is OKay?

I am trying to get max. freq on gpio pin. please suggess a solution why
console respond too slow after upgrading board to new kernel.

Thank you for your time in advance.

--
miniarm

Take a look into "/proc/interrupts". When I tried the RT patch the last
time the serial driver went amok and created about 500,000 interrupts per
char.
And: the S3C2440 CPU has a timer with only 16 bit width. There is no HRT
driver present for this timer (AFAIK). So, RT Preempt will not run as
expected on this CPU.

Hello Juergen,

Some developer is saying that rt kernel won't work with mini2440, is that
true? if so then what is the solution for this problem? 

I want to get maximum freq. from the gpio pin. when i try to read the pin,
read system call takes maximum time, so i thought if i use rt kernel that
will solve the problem.

Plz help.

--miniarm

if you want max. speed driving a GPIO (PWM?) in software, you shouldn't use
a operating system like Linux or something similar. Driving a GPIO with
high frequency in software is a really bad idea.

I told him that Juergen, but he does not believe it,

Dear Andre,

http://www.friendlyarm.net/forum/topic/3476, people are saying here that
they have got freq. above 400 khz using pwm, that's why i am trying to
achieve at-least 800 khz instead of 382 khz.

your help or guidance will be much appreciated.


regards,
miniarm

finally successfully ported 2.6.39 kernel to board, and compiled
mini2440_pwm.c program as a module, load to kernel, when try to run
pwm_test program it gives increment in freq. but buzzer is not working,
However if i export pin to /sys/gpio interface and add value 1 to 'value'
parameter, buzzer is working perfectly.

what could be the change? what i am missing here? why buzzer is not working
with .39 kernel, have you encounter the same problem?

Please let me know.

--
miniarm

Hello

Finally successfully installed and run 2.6.39  kernel into the board with
yaffs2 file system, system is running perfectly fine, also solved the
problem of buzzer, ( the new kernel comes with different syntax of ioctl ),
but still not able to get good freq. 

real    0m 2.20s
user    0m 0.70s
sys     0m 1.50s

Here are the reading for running a c program that drive the motor 10 times,
in 2.6.32 kernel total time was 1.91s, but after upgrading kernel it is
2.20s. don't know why, what could be the proble?

@Andre, can you please help me out there?

--
miniarm