linux/drivers/rapidio
Alexandre Bounine 04379dffdd rapidio/tsi721: fix tasklet termination in dma channel release
This patch is a modification of the patch originally proposed by
Xiaotian Feng <xtfeng@gmail.com>: 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 <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Xiaotian Feng <xtfeng@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Galbraith <bitbucket@online.de>
Cc: <stable@vger.kernel.org>	[3.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-04 07:55:49 -08:00
..
devices rapidio/tsi721: fix tasklet termination in dma channel release 2014-03-04 07:55:49 -08:00
switches Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2013-07-13 14:52:21 -07:00
Kconfig rapidio: convert switch drivers to modules 2013-07-03 16:08:04 -07:00
Makefile rapidio: add modular build option for the subsystem core 2013-07-03 16:08:05 -07:00
rio-access.c
rio-driver.c rapidio: convert bus code to use dev_groups 2013-10-16 18:36:03 -07:00
rio-scan.c rapidio: change endpoint device name format 2013-07-03 16:08:05 -07:00
rio-sysfs.c rapidio: convert bus code to use dev_groups 2013-10-16 18:36:03 -07:00
rio.c rapidio: fix use after free in rio_unregister_scan() 2013-07-31 14:41:02 -07:00
rio.h rapidio: convert bus code to use dev_groups 2013-10-16 18:36:03 -07:00