Re: MOXA I/O errors on 2.6.28+

From: Jan Kasprzak
Date: Sat Mar 14 2009 - 18:42:03 EST


Alan Cox wrote:
: On Sat, 14 Mar 2009 22:36:30 +0100
: Jan Kasprzak <kas@xxxxxxxxxx> wrote:
:
: > I have several servers with MOXA C320 serial boards. Starting with 2.6.28,
: > some ports on MOXA boards sometimes get to a state where open("/dev/ttyMX<n>")
: > returns -EIO. I use the servers with MOXA boards as serial console hubs,
: > and I think the EIO state is caused by the remote getty or the whole remote
: > server being restarted.
:
: Sounds like a refcount bug.
:
: > 2.6.27 is OK, 2.6.28 and 2.6.29-rc8 is faulty. I can git bisect
: > if you want (I have a spare server which I can reboot at will).
:
: Might be useful but let me take a look first, chances are you've provided
: enough information

It is this one:

d450b5a0196b6442cf3f29fc611d9c8daa56b559 tty: kref usage for isicom and moxa.

Reverting this commit on top of 2.6.29-rc8 (and resolving a single conflict
the revert introduces in drivers/char/moxa.c) makes the problem disappear.

-Yenya

--
| Jan "Yenya" Kasprzak <kas at {fi.muni.cz - work | yenya.net - private}> |
| GPG: ID 1024/D3498839 Fingerprint 0D99A7FB206605D7 8B35FCDE05B18A5E |
| http://www.fi.muni.cz/~kas/ Journal: http://www.fi.muni.cz/~kas/blog/ |
>> If you find yourself arguing with Alan Cox, youâre _probably_ wrong. <<
>> --James Morris in "How and Why You Should Become a Kernel Hacker" <<
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