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author | Eugenia Emantayev <eugenia@mellanox.com> | 2013-07-25 19:21:23 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-21 09:22:55 -0800 |
commit | 50e0289d813aceddedf962ea92299b68ac264671 (patch) | |
tree | 1fb703f0c52854f2cea4f9fcd2d3e047fc14a7b7 /drivers/scsi/megaraid | |
parent | 9f6bb0c21dbe0f0604a5fd3f8717677ffccd7aed (diff) |
net/mlx4_en: Fix BlueFlame race
commit 2d4b646613d6b12175b017aca18113945af1faf3 upstream.
Fix a race between BlueFlame flow and stamping in post send flow.
Example:
SW: Build WQE 0 on the TX buffer, except the ownership bit
SW: Set ownership for WQE 0 on the TX buffer
SW: Ring doorbell for WQE 0
SW: Build WQE 1 on the TX buffer, except the ownership bit
SW: Set ownership for WQE 1 on the TX buffer
HW: Read WQE 0 and then WQE 1, before doorbell was rung/BF was done for WQE 1
HW: Produce CQEs for WQE 0 and WQE 1
SW: Process the CQEs, and stamp WQE 0 and WQE 1 accordingly (on the TX buffer)
SW: Copy WQE 1 from the TX buffer to the BF register - ALREADY STAMPED!
HW: CQE error with index 0xFFFF - the BF WQE's control segment is STAMPED,
so the BF index is 0xFFFF. Error: Invalid Opcode.
As a result QP enters the error state and no traffic can be sent.
Solution:
When stamping - do not stamp last completed wqe.
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Vinson Lee <vlee@twopensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/scsi/megaraid')
0 files changed, 0 insertions, 0 deletions