Hello Matan,
On Mon, May 21, 2018 at 07:48:03PM +0000, Matan Azrad wrote:
> The fail-safe PMD registers to RMV event for each removable sub-device
> port in order to cleanup the sub-device resources and switch the Tx
> sub-device directly when it is plugged-out.
>
> During removal time, the fail-safe PMD stops and closes the sub-device
> but it doesn't unregister the LSC and RMV callbacks of the sub-device
> port.
>
> It can lead the callbacks to be called for a port which is no more
> associated with the fail-safe sub-device, because there is not a
> guarantee that a sub-device gets the same port ID for each plug-in
> process. This port, for example, may belong to another sub-device of a
> different fail-safe device.
>
> Unregister the LSC and RMV callbacks for sub-devices which are not
> used.
>
> Fixes: 598fb8aec6f6 ("net/failsafe: support device removal")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Matan Azrad <ma...@mellanox.com>
> ---
> drivers/net/failsafe/failsafe_ether.c | 22 ++++++++++++++++++++++
> drivers/net/failsafe/failsafe_ops.c | 5 +++++
> drivers/net/failsafe/failsafe_private.h | 5 +++++
> 3 files changed, 32 insertions(+)
>
> V2:
> Improve the commit log and add code comments for the new sub-dev fields
> (Ophir suggestion).
>
>
> diff --git a/drivers/net/failsafe/failsafe_ether.c
> b/drivers/net/failsafe/failsafe_ether.c
> index 733e95d..2bbee82 100644
> --- a/drivers/net/failsafe/failsafe_ether.c
> +++ b/drivers/net/failsafe/failsafe_ether.c
> @@ -260,6 +260,7 @@
> sdev->state = DEV_ACTIVE;
> /* fallthrough */
> case DEV_ACTIVE:
> + failsafe_eth_dev_unregister_callbacks(sdev);
> rte_eth_dev_close(PORT_ID(sdev));
> sdev->state = DEV_PROBED;
> /* fallthrough */
> @@ -321,6 +322,27 @@
> }
>
> void
> +failsafe_eth_dev_unregister_callbacks(struct sub_device *sdev)
> +{
> + if (sdev == NULL)
> + return;
> + if (sdev->rmv_callback) {
> + rte_eth_dev_callback_unregister(PORT_ID(sdev),
> + RTE_ETH_EVENT_INTR_RMV,
> + failsafe_eth_rmv_event_callback,
> + sdev);
> + sdev->rmv_callback = 0;
I agree with Ophir here, either the return value should not be ignored,
and rmv_callback should only be set to 0 on success, or a proper
justification (and an accompanying comment) should be given.
The issue I could see is that even on error, there won't be a process to
try again unregistering the callback.
Maybe this could be added in failsafe_dev_remove()? Something like
FOREACH_SUBDEV(sdev, i, dev) {
if (sdev->rmv_callback && sdev->state <= DEV_PROBED)
if (rte_eth_dev_callback_unregister(...) == 0)
sdev->rmv_callback = 0;
/* same for lsc_callback */
}
Does it make sense to you? Do you think this is necessary, or should we
ignore this?
Thanks,
--
Gaëtan Rivet
6WIND
