net: mana: Clear RDMA teardown and suspend state in mana_rdma_probe()

mana_rdma_remove() sets gd->rdma_teardown to stop mana_rdma_service_handle() from acting on servicing events, but nothing ever clears it. A hardware service reset (GDMA_EQE_HWC_RESET_REQUEST) goes through mana_gd_suspend() -> mana_rdma_remove() and mana_gd_resume() -> mana_rdma_probe(), so from the first reset onwards every GDMA_EQE_HWC_SOC_SERVICE event returns early and RDMA suspend/resume servicing is silently dropped for the life of the device. gd->is_suspended has the same problem: it is set when servicing removes the adev and is cleared only by a matching resume. A reset while RDMA is suspended re-adds the adev but leaves is_suspended set, so a later resume event calls add_adev() on top of a live gd->adev and leaks it. This is currently masked by the rdma_teardown bug. Clear both in mana_rdma_probe(). On the reset path mana_rdma_remove() has closed the gate and drained the service workqueue, so clear is_suspended first and re-open the gate with smp_store_release(), paired with smp_load_acquire() in the handler, so the handler cannot observe an open gate with a stale is_suspended. On the initial probe path the gate was never closed and both flags are already clear. This does not order gd->adev, which add_adev() publishes afterwards. A servicing event arriving in that window is still dropped, as it is in mainline today on the initial probe path; closing it needs probe and the handler to be serialized and is left to a separate change.

LLLong Li committed 2 months ago