db9ae8fec7
Put bus_reset_work into its own workqueue. By doing this, forward
progress of bus_reset_work() is guaranteed if the work is switched over
to a rescuer thread.
Switching work to a rescuer thread happens if a new worker thread could
not be allocated in certain time (MAYDAY_INITIAL_TIMEOUT, typically 10
ms). This might not be possible under high memory pressure or even on a
heavily loaded embedded system running a slow serial console.
The former deadlock occured in the following situation:
The rescuer thread ran
fw_device_init->read_config_rom->read_rom->fw_run_transaction.
fw_run_transaction blocked waiting for the completion object.
This completion object would have been completed in bus_reset_work,
but this work was never executed in the rescuer thread due to its
strictly sequential behaviour.
[Stefan R.: Removed WQ_NON_REENTRANT flag from allocation because
it is no longer needed in current kernels. Add it back if you backport
to kernels older than 3.7, i.e. one which does not contain
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| .. | ||
| Kconfig | ||
| Makefile | ||
| core-card.c | ||
| core-cdev.c | ||
| core-device.c | ||
| core-iso.c | ||
| core-topology.c | ||
| core-transaction.c | ||
| core.h | ||
| init_ohci1394_dma.c | ||
| net.c | ||
| nosy-user.h | ||
| nosy.c | ||
| nosy.h | ||
| ohci.c | ||
| ohci.h | ||
| sbp2.c | ||