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author | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2010-10-13 11:39:46 (GMT) |
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committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2011-05-10 20:53:45 (GMT) |
commit | 6ea9e7bbfc389a12d52646449a201fe933ccd663 (patch) | |
tree | f84e89a394d45db4f30e1286966f69be62f203da /drivers/firewire/core-card.c | |
parent | 13882a82ee1646336c3996c93b4a560a55d2a419 (diff) | |
download | linux-fsl-qoriq-6ea9e7bbfc389a12d52646449a201fe933ccd663.tar.xz |
firewire: core: use non-reentrant workqueue with rescuer
firewire-core manages the following types of work items:
fw_card.br_work:
- resets the bus on a card and possibly sends a PHY packet before that
- does not sleep for long or not at all
- is scheduled via fw_schedule_bus_reset() by
- firewire-ohci's pci_probe method
- firewire-ohci's set_config_rom method, called by kernelspace
protocol drivers and userspace drivers which add/remove
Configuration ROM descriptors
- userspace drivers which use the bus reset ioctl
- itself if the last reset happened less than 2 seconds ago
fw_card.bm_work:
- performs bus management duties
- usually does not (but may in corner cases) sleep for long
- is scheduled via fw_schedule_bm_work() by
- firewire-ohci's self-ID-complete IRQ handler tasklet
- firewire-core's fw_device.work instances whenever the root node
device was (successfully or unsuccessfully) discovered,
refreshed, or rediscovered
- itself in case of resource allocation failures or in order to
obey the 125ms bus manager arbitration interval
fw_device.work:
- performs node probe, update, shutdown, revival, removal; including
kernel driver probe, update, shutdown and bus reset notification to
userspace drivers
- usually sleeps moderately long, in corner cases very long
- is scheduled by
- firewire-ohci's self-ID-complete IRQ handler tasklet via the
core's fw_node_event
- firewire-ohci's pci_remove method via core's fw_destroy_nodes/
fw_node_event
- itself during retries, e.g. while a node is powering up
iso_resource.work:
- accesses registers at the Isochronous Resource Manager node
- usually does not (but may in corner cases) sleep for long
- is scheduled via schedule_iso_resource() by
- the owning userspace driver at addition and removal of the
resource
- firewire-core's fw_device.work instances after bus reset
- itself in case of resource allocation if necessary to obey the
1000ms reallocation period after bus reset
fw_card.br_work instances should not, and instances of the others must
not, be executed in parallel by multiple CPUs -- but were not protected
against that. Hence allocate a non-reentrant workqueue for them.
fw_device.work may be used in the memory reclaim path in case of SBP-2
device updates. Hence we need a workqueue with rescuer and cannot use
system_nrt_wq.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'drivers/firewire/core-card.c')
-rw-r--r-- | drivers/firewire/core-card.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c index f05fc7b..bb8c4d2 100644 --- a/drivers/firewire/core-card.c +++ b/drivers/firewire/core-card.c @@ -228,8 +228,8 @@ void fw_schedule_bus_reset(struct fw_card *card, bool delayed, bool short_reset) /* Use an arbitrary short delay to combine multiple reset requests. */ fw_card_get(card); - if (!schedule_delayed_work(&card->br_work, - delayed ? DIV_ROUND_UP(HZ, 100) : 0)) + if (!queue_delayed_work(fw_wq, &card->br_work, + delayed ? DIV_ROUND_UP(HZ, 100) : 0)) fw_card_put(card); } EXPORT_SYMBOL(fw_schedule_bus_reset); @@ -241,7 +241,7 @@ static void br_work(struct work_struct *work) /* Delay for 2s after last reset per IEEE 1394 clause 8.2.1. */ if (card->reset_jiffies != 0 && time_before64(get_jiffies_64(), card->reset_jiffies + 2 * HZ)) { - if (!schedule_delayed_work(&card->br_work, 2 * HZ)) + if (!queue_delayed_work(fw_wq, &card->br_work, 2 * HZ)) fw_card_put(card); return; } |