Searched hist:d0d68b86 (Results 1 – 2 of 2) sorted by relevance
/openbmc/linux/include/linux/mlx4/ |
H A D | cmd.h | d0d68b86 Mon Oct 04 07:11:34 CDT 2010 Jack Morgenstein <jackm@dev.mellanox.co.il> IB/mlx4: Signal node desc changes to SM by using FW to generate trap 144
The Node Description cannot be changed via MADs (it is read-only). Until now, it was changed in the driver via sysfs, and the new Node Description was simply inserted by the driver into MAD responses (replacing the description returned by FW).
System startup scripts use the sysfs interface to change the node description at driver startup to show the hostname, etc. However, this has a race condition: the SM could discover the original FW node description rather than the system-specific description if it queried the port before the startup scripts finish running.
For mlx4, we fix this with a new FW command (SET_NODE) that allows passing the new node description to FW. When this command is invoked, FW sends a trap 144 to the SM. When it gets this trap, the SM can query the node to obtain the new node description -- thus eliminating the effects of the race.
This patch simply calls SET_NODE command when a new node description is entered via sysfs (thus causing trap 144 to be issued by the FW). We ignore all failures of the SET_NODE command (including those caused by using a device FW that predates the SET_NODE command), since in that case things work just as before.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Roland Dreier <rolandd@cisco.com> d0d68b86 Mon Oct 04 07:11:34 CDT 2010 Jack Morgenstein <jackm@dev.mellanox.co.il> IB/mlx4: Signal node desc changes to SM by using FW to generate trap 144 The Node Description cannot be changed via MADs (it is read-only). Until now, it was changed in the driver via sysfs, and the new Node Description was simply inserted by the driver into MAD responses (replacing the description returned by FW). System startup scripts use the sysfs interface to change the node description at driver startup to show the hostname, etc. However, this has a race condition: the SM could discover the original FW node description rather than the system-specific description if it queried the port before the startup scripts finish running. For mlx4, we fix this with a new FW command (SET_NODE) that allows passing the new node description to FW. When this command is invoked, FW sends a trap 144 to the SM. When it gets this trap, the SM can query the node to obtain the new node description -- thus eliminating the effects of the race. This patch simply calls SET_NODE command when a new node description is entered via sysfs (thus causing trap 144 to be issued by the FW). We ignore all failures of the SET_NODE command (including those caused by using a device FW that predates the SET_NODE command), since in that case things work just as before. Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Roland Dreier <rolandd@cisco.com>
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/openbmc/linux/drivers/infiniband/hw/mlx4/ |
H A D | main.c | d0d68b86 Mon Oct 04 07:11:34 CDT 2010 Jack Morgenstein <jackm@dev.mellanox.co.il> IB/mlx4: Signal node desc changes to SM by using FW to generate trap 144
The Node Description cannot be changed via MADs (it is read-only). Until now, it was changed in the driver via sysfs, and the new Node Description was simply inserted by the driver into MAD responses (replacing the description returned by FW).
System startup scripts use the sysfs interface to change the node description at driver startup to show the hostname, etc. However, this has a race condition: the SM could discover the original FW node description rather than the system-specific description if it queried the port before the startup scripts finish running.
For mlx4, we fix this with a new FW command (SET_NODE) that allows passing the new node description to FW. When this command is invoked, FW sends a trap 144 to the SM. When it gets this trap, the SM can query the node to obtain the new node description -- thus eliminating the effects of the race.
This patch simply calls SET_NODE command when a new node description is entered via sysfs (thus causing trap 144 to be issued by the FW). We ignore all failures of the SET_NODE command (including those caused by using a device FW that predates the SET_NODE command), since in that case things work just as before.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Roland Dreier <rolandd@cisco.com> d0d68b86 Mon Oct 04 07:11:34 CDT 2010 Jack Morgenstein <jackm@dev.mellanox.co.il> IB/mlx4: Signal node desc changes to SM by using FW to generate trap 144 The Node Description cannot be changed via MADs (it is read-only). Until now, it was changed in the driver via sysfs, and the new Node Description was simply inserted by the driver into MAD responses (replacing the description returned by FW). System startup scripts use the sysfs interface to change the node description at driver startup to show the hostname, etc. However, this has a race condition: the SM could discover the original FW node description rather than the system-specific description if it queried the port before the startup scripts finish running. For mlx4, we fix this with a new FW command (SET_NODE) that allows passing the new node description to FW. When this command is invoked, FW sends a trap 144 to the SM. When it gets this trap, the SM can query the node to obtain the new node description -- thus eliminating the effects of the race. This patch simply calls SET_NODE command when a new node description is entered via sysfs (thus causing trap 144 to be issued by the FW). We ignore all failures of the SET_NODE command (including those caused by using a device FW that predates the SET_NODE command), since in that case things work just as before. Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Roland Dreier <rolandd@cisco.com>
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