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author | Dave Jiang <dave.jiang@intel.com> | 2013-02-07 22:38:32 +0100 |
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committer | Vinod Koul <vinod.koul@intel.com> | 2013-02-12 17:27:21 +0100 |
commit | 4dec23d7718e6f1f5e1773698d112025169e7d49 (patch) | |
tree | 2d39626f26b0b8cbbdcb246188ec5b2c7494fd8d /drivers/dma/Makefile | |
parent | dw_dmac: add support for Lynxpoint DMA controllers (diff) | |
download | linux-4dec23d7718e6f1f5e1773698d112025169e7d49.tar.xz linux-4dec23d7718e6f1f5e1773698d112025169e7d49.zip |
ioatdma: fix race between updating ioat->head and IOAT_COMPLETION_PENDING
There is a race that can hit during __cleanup() when the ioat->head pointer is
incremented during descriptor submission. The __cleanup() can clear the
PENDING flag when it does not see any active descriptors. This causes new
submitted descriptors to be ignored because the COMPLETION_PENDING flag is
cleared. This was introduced when code was adapted from ioatdma v1 to ioatdma
v2. For v2 and v3, IOAT_COMPLETION_PENDING flag will be abandoned and a new
flag IOAT_CHAN_ACTIVE will be utilized. This flag will also be protected under
the prep_lock when being modified in order to avoid the race.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Williams <djbw@fb.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/Makefile')
0 files changed, 0 insertions, 0 deletions