diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2014-02-20 04:19:35 +0400 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2014-02-25 21:44:20 +0400 |
| commit | da87ca4d4ca101f177fffd84f1f0a5e4c0343557 (patch) | |
| tree | 5b2be4209f11af7a3df5cf68997e9547612481ef /drivers/dma/ioat/dma.h | |
| parent | 6d0abeca3242a88cab8232e4acd7e2bf088f3bc2 (diff) | |
| download | linux-da87ca4d4ca101f177fffd84f1f0a5e4c0343557.tar.xz | |
ioat: fix tasklet tear down
Since commit 77873803363c "net_dma: mark broken" we no longer pin dma
engines active for the network-receive-offload use case. As a result
the ->free_chan_resources() that occurs after the driver self test no
longer has a NET_DMA induced ->alloc_chan_resources() to back it up. A
late firing irq can lead to ksoftirqd spinning indefinitely due to the
tasklet_disable() performed by ->free_chan_resources(). Only
->alloc_chan_resources() can clear this condition in affected kernels.
This problem has been present since commit 3e037454bcfa "I/OAT: Add
support for MSI and MSI-X" in 2.6.24, but is now exposed. Given the
NET_DMA use case is deprecated we can revisit moving the driver to use
threaded irqs. For now, just tear down the irq and tasklet properly by:
1/ Disable the irq from triggering the tasklet
2/ Disable the irq from re-arming
3/ Flush inflight interrupts
4/ Flush the timer
5/ Flush inflight tasklets
References:
https://lkml.org/lkml/2014/1/27/282
https://lkml.org/lkml/2014/2/19/672
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Reported-by: Mike Galbraith <bitbucket@online.de>
Reported-by: Stanislav Fomichev <stfomichev@yandex-team.ru>
Tested-by: Mike Galbraith <bitbucket@online.de>
Tested-by: Stanislav Fomichev <stfomichev@yandex-team.ru>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dma/ioat/dma.h')
| -rw-r--r-- | drivers/dma/ioat/dma.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h index 11fb877ddca9..e982f00a9843 100644 --- a/drivers/dma/ioat/dma.h +++ b/drivers/dma/ioat/dma.h @@ -356,6 +356,7 @@ bool ioat_cleanup_preamble(struct ioat_chan_common *chan, void ioat_kobject_add(struct ioatdma_device *device, struct kobj_type *type); void ioat_kobject_del(struct ioatdma_device *device); int ioat_dma_setup_interrupts(struct ioatdma_device *device); +void ioat_stop(struct ioat_chan_common *chan); extern const struct sysfs_ops ioat_sysfs_ops; extern struct ioat_sysfs_entry ioat_version_attr; extern struct ioat_sysfs_entry ioat_cap_attr; |