Serieal console on Samsung S3C6410 ARM11 CPU (Was [ANNOUNCE] 3.0.6-rt17)

[Juergen Beisert <jbe@pengutronix.de>]

Thomas Gleixner wrote:
> I'm pleased to announce the 3.0.6-rt17 release.

I have no idea where to search, but when I'm using the 3.0.6-rt17 on my
Samsung S3C6410 ARM based system, the UART (serial console) does not work as 
expected. Typing only one char at a time is okay. Typing two chars 
immediately makes the system using 100 % CPU load and takes about 2 seconds 
to respond. It seems the interrupt handling is broken in the UART driver, but 
I don't know how to fix it.

This with a simple cursor up (one char to get the last command) and a small 
pause to the next "ENTER" char:

root@mini6410:~ cat /proc/interrupts | grep 18:
 18:    5739107  s3c-uart  s3c6400-uart

Same again:

root@mini6410:~ cat /proc/interrupts | grep 18:
 18:    5739113  s3c-uart  s3c6400-uart

6 interrupts seems reasonable.

Now with cursor up and SPACE immediately, then a pause for ENTER:

root@mini6410:~ cat /proc/interrupts | grep 18:
 18:    5923815  s3c-uart  s3c6400-uart

184702 interrupts looks strange.

jbe

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Pengutronix e.K.                              | Juergen Beisert             |
Linux Solutions for Science and Industry      | http://www.pengutronix.de/  |