summaryrefslogtreecommitdiff
path: root/drivers/dma/ioat/dma.h
diff options
context:
space:
mode:
authorDan Williams <dan.j.williams@intel.com>2014-02-20 04:19:35 +0400
committerDan Williams <dan.j.williams@intel.com>2014-02-25 21:44:20 +0400
commitda87ca4d4ca101f177fffd84f1f0a5e4c0343557 (patch)
tree5b2be4209f11af7a3df5cf68997e9547612481ef /drivers/dma/ioat/dma.h
parent6d0abeca3242a88cab8232e4acd7e2bf088f3bc2 (diff)
downloadlinux-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.h1
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;