android_kernel_motorola_sm6225/drivers/net/ethernet/intel/e1000e
Bruce Allan 5f4a780ddd e1000e: hitting BUG_ON() from napi_enable
Based on a patch from Mike McElroy created against the out-of-tree e1000e
driver:

Hitting the BUG_ON in napi_enable(). Code inspection shows that this can
only be triggered by calling napi_enable() twice without an intervening
napi_disable().

I saw the following sequence of events in the stack trace:

1) We simulated a cable pull using an Extreme switch.
2) e1000_tx_timeout() was entered.
3) e1000_reset_task() was called. Saw the message from e_err() in the
console log.
4) e1000_reinit_locked was called. This function calls e1000_down() and
e1000_up(). These functions call napi_disable() and napi_enable()
respectively.
5) Then on another thread, a monitor task saw carrier was down and executed
'ip set link down' and 'ip set link up' commands.
6) Saw the '_E1000_RESETTING'warning fron the e1000_close function.
7) Either the e1000_open() executed between the e1000_down() and e1000_up()
calls in step 4 or the e1000_open() call executed after the e1000_up()
call.  In either case, napi_enable() is called twice which triggers the
BUG_ON.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Cc: Mike McElroy <mike.mcelroy@stratus.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2011-12-05 00:12:22 -08:00
..
80003es2lan.c e1000e: make function tables const 2011-10-05 02:52:21 -07:00
82571.c e1000e: make function tables const 2011-10-05 02:52:21 -07:00
defines.h
e1000.h e1000e: Avoid wrong check on TX hang 2011-12-05 00:12:11 -08:00
ethtool.c net: sweep-up some straglers in strlcpy conversion of .get_drvinfo routines 2011-11-16 17:38:55 -05:00
hw.h
ich8lan.c e1000e: demote a debugging WARN to a debug log message 2011-11-02 16:54:53 -07:00
lib.c
Makefile
netdev.c e1000e: hitting BUG_ON() from napi_enable 2011-12-05 00:12:22 -08:00
param.c drivers/net: Add module.h to drivers who were implicitly using it 2011-10-31 19:31:07 -04:00
phy.c