On Mon, Oct 14, 2002 at 01:39:07PM +0200, Bernd Petrovitsch wrote:
> Hi all!
>
> Is is normal/correct/intended that an open() of /dev/ttyS1 blocks?
> ---- snip ----
> {81}strace ./test-open /dev/ttyS0
> [...]
> open("/dev/ttyS0", O_RDONLY|O_NONBLOCK) = 3
> close(3) = 0
> open("/dev/ttyS0", O_RDONLY|O_NONBLOCK|O_LARGEFILE) = 3
> close(3) = 0
> open("/dev/ttyS0", O_RDONLY|O_LARGEFILE) = 3
> close(3) = 0
> _exit(0) = ?
> {82}strace ./test-open /dev/ttyS1
> [...]
> open("/dev/ttyS1", O_RDONLY|O_NONBLOCK) = 3
> close(3) = 0
> open("/dev/ttyS1", O_RDONLY|O_NONBLOCK|O_LARGEFILE) = 3
> close(3) = 0
> open("/dev/ttyS1", O_RDONLY|O_LARGEFILE <unfinished ...>
> {83}lsof /dev/ttyS0
> {84}lsof /dev/ttyS1
> {85}uname -a
> Linux xxx 2.4.20-pre10aa1 #6 Fri Oct 11 13:41:20 CEST 2002 i686 unknown
> ---- snip ----
>
> The second one was terminated with a Ctrl-C.
> Nothing was connected to none of the ports.
> Is there a reason that an open() on /dev/ttyS0 works and blocks
> on /dev/ttyS1?
stty -aF /dev/ttyS0
stty -aF /dev/ttyS1
I bet ttyS0 has clocal set, whereas ttyS1 doesn't.
--
Russell King (rmk@arm.linux.org.uk) The developer of ARM Linux
http://www.arm.linux.org.uk/personal/aboutme.html
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This archive was generated by hypermail 2b29 : Tue Oct 15 2002 - 22:00:49 EST