On Fri, 21 Feb 2014, Alexandre Bounine wrote:
This patch is a modification of the patch originally proposed
by Xiaotian Feng [off-list ref]: https://lkml.org/lkml/2012/11/5/413
This new version disables DMA channel interrupts and ensures that the tasklet
wil not be scheduled again before calling tasklet_kill().
Unfortunately the updated patch was not released at that time due to planned
rework of Tsi721 mport driver to use threaded interrupts (which has yet to
happen).
Recently the issue was reported again: https://lkml.org/lkml/2014/2/19/762.
Description from the original Xiaotian's patch:
"Some drivers use tasklet_disable in device remove/release process,
tasklet_disable will inc tasklet->count and return. If the tasklet is
not handled yet under some softirq pressure, the tasklet will be
placed on the tasklet_vec, never have a chance to be excuted. This
might lead to a heavy loaded ksoftirqd, wakeup with pending_softirq,
but tasklet is disabled. tasklet_kill should be used in this case."
This patch is applicable to kernel versions starting from v3.5.
Signed-off-by: Alexandre Bounine <redacted>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Xiaotian Feng <redacted>
Cc: Thomas Gleixner <redacted>
Cc: Mike Galbraith <redacted>
Cc: <redacted>
Reviewed-by: Thomas Gleixner <redacted>