Re: WARN_ON() hit in fsl bitbanged phy driver

Rune Torgersen wrote:

Scott Wood wrote:

quoted

Rune Torgersen wrote:

quoted

I hit the following WARN_ON when using mii-tools agains a ethernet
interface using a bit-banged mii interface

It looks like the kernel thinks it's in an interrupt, even though it
clearly isn't from the backtrace.  Presumably, something
slept from an
interrupt handler; try turning on sleep-in-spinlock debugging.

I turned on sleep-in-spinlock and it did not reveal anything. I'm trying
some other debug options.

quoted

The root cause was probably something other than the phy code.

I'm not so sure, because it only happens when I run mii-tool agains the
interface useing the bit-banged driver, and then only the first time.

OK, it seems I should have checked 2.6.24 instead of head-of-tree; 
softirq.c:139 is a different assertion than I thought.  It's not 
in_irq(), but irqs_disabled().  fs_ioctl() is disabling interrupts, and 
spin_unlock_bh() doesn't like that.  The current use of mutexes likes it 
even less.  The locking should be moved inside the phy bus 
implementation, if it's needed at all.

It only happens once because it's a WARN_ON_ONCE(). :-)

-Scott