Re: MOXA I/O errors on 2.6.28+

[Jan Kasprzak <kas@fi.muni.cz>]

Alan Cox wrote:
: On Sat, 14 Mar 2009 22:36:30 +0100
: Jan Kasprzak <kas@fi.muni.cz> 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}> |
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| http://www.fi.muni.cz/~kas/    Journal: http://www.fi.muni.cz/~kas/blog/ |
>>  If you find yourself arguing with Alan Cox, you’re _probably_ wrong.  <<
>>     --James Morris in "How and Why You Should Become a Kernel Hacker"  <<