Re: BUG: bad unlock balance detected! e1000e

From: Andrew Morton
Date: Tue Dec 09 2008 - 18:08:31 EST


On Tue, 9 Dec 2008 12:03:37 +0100
Frederik Deweerdt <frederik.deweerdt@xxxxxxxx> wrote:

> It some error checking is missing in e1000e: debug contention on NVM
> SWFLAG
> On Mon, Dec 08, 2008 at 12:24:09PM +0100, Zdenek Kabelac wrote:
> > Hi
> >
> > During occasional scan of message log - I've found out this BUG which
> > happened on Dec3 with the -rc7 from that day.
> > (So if it's now fixed in current git feel free to ignore :))
> >
> > My machine T61 - C2D, 2GB, 64bit kernel - message appeared during
> > shutdown and was actually not noticed by me...
> >
> >
> > NetworkManager: <WARN> nm_signal_handler(): Caught signal 15,
> > shutting down normally.
> > NetworkManager: <info> (eth0): now unmanaged
> > NetworkManager: <info> (eth0): device state change: 3 -> 1
> > NetworkManager: <info> (eth0): cleaning up...
> > NetworkManager: <info> (eth0): taking down device.
> >
> > =====================================
> > [ BUG: bad unlock balance detected! ]
> > -------------------------------------

(top-posting repaired. Please don't do that!!!).

> Hello Zdenek,
>
> This could be due to 717d438d1fde94decef874b9808379d1f4523453
> "e1000e: debug contention on NVM SWFLAG"
> Error handling is missing from e1000_reset_hw_ich8lan so it may happen
> that we don't acquire the nvm_mutex if the card times out.
>
> Adding Thomas to CC.

yup. 2.6.27 needs fixing also.

Like this?

From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>

=====================================
[ BUG: bad unlock balance detected! ]
-------------------------------------

A regression added by 717d438d1fde94decef874b9808379d1f4523453 ("e1000e:
debug contention on NVM SWFLAG").

Reported-by: "Zdenek Kabelac" <zdenek.kabelac@xxxxxxxxx>
Cc: Frederik Deweerdt <frederik.deweerdt@xxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

drivers/net/e1000e/ich8lan.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff -puN drivers/net/e1000e/ich8lan.c~drivers-net-e1000e-ich8lanc-fix-locking drivers/net/e1000e/ich8lan.c
--- a/drivers/net/e1000e/ich8lan.c~drivers-net-e1000e-ich8lanc-fix-locking
+++ a/drivers/net/e1000e/ich8lan.c
@@ -400,6 +400,7 @@ static s32 e1000_acquire_swflag_ich8lan(
{
u32 extcnf_ctrl;
u32 timeout = PHY_CFG_TIMEOUT;
+ s32 ret = 0;

might_sleep();

@@ -427,11 +428,11 @@ static s32 e1000_acquire_swflag_ich8lan(
extcnf_ctrl &= ~E1000_EXTCNF_CTRL_SWFLAG;
ew32(EXTCNF_CTRL, extcnf_ctrl);
nvm_owner = -1;
- mutex_unlock(&nvm_mutex);
- return -E1000_ERR_CONFIG;
+ ret = -E1000_ERR_CONFIG;
}

- return 0;
+ mutex_unlock(&nvm_mutex);
+ return ret;
}

/**
_

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