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author | 2013-01-31 07:43:22 +0000 | |
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committer | 2013-03-08 00:03:26 -0800 | |
commit | e757e3e198795bfc56a28b41c494bcb27c0ee2ab (patch) | |
tree | 3a1996635f2c530e798f34f495bab308199b42ba /drivers/net/ethernet/intel/e1000e/netdev.c | |
parent | ipv6 flowlabel: add __rcu annotations (diff) | |
download | linux-e757e3e198795bfc56a28b41c494bcb27c0ee2ab.tar.gz linux-e757e3e198795bfc56a28b41c494bcb27c0ee2ab.tar.bz2 linux-e757e3e198795bfc56a28b41c494bcb27c0ee2ab.zip |
ixgbevf: Make next_to_watch a pointer and adjust memory barriers to avoid races
This change is meant to address several race issues that become possible
because next_to_watch could possibly be set to a value that shows that the
descriptor is done when it is not. In order to correct that we instead make
next_to_watch a pointer that is set to NULL during cleanup, and set to the
eop_desc after the descriptor rings have been written.
To enforce proper ordering the next_to_watch pointer is not set until after
a wmb writing the values to the last descriptor in a transmit. In order to
guarantee that the descriptor is not read until after the eop_desc we use the
read_barrier_depends which is only really necessary on the alpha architecture.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net/ethernet/intel/e1000e/netdev.c')
0 files changed, 0 insertions, 0 deletions