In online FW upgrade process, the memblaze Pblaze4 NVMe device requires an extra delay during controller reset process. The following patch email from HGST describes the similar issue in detail.



Subject: [PATCH v3] nvme/quirk: Add a delay before checking for adapter readiness


When disabling the controller, the specification says the register NVME_REG_CC should be written and then driver needs to wait the adapter to be ready, which is checked by reading another register bit (NVME_CSTS_RDY). There's a timeout validation in this checking, so in case this timeout is reached the driver gives up and removes the adapter from the system.


After a firmware activation procedure, the PCI_DEVICE(0x1c58, 0x0003) (HGST adapter) end up being removed if we issue a reset_controller, because driver keeps verifying the NVME_REG_CSTS until the timeout is reached. This patch adds a necessary quirk for this adapter, by introducing a delay before nvme_wait_ready(), so the reset procedure is able to be completed. This quirk is needed because just increasing the timeout is not enough in case of this adapter - the driver must wait before start reading NVME_REG_CSTS register on this specific device.



The standard Linux NVMe driver now has quirk “NVME_QUIRK_DELAY_BEFORE_CHK_RDY” for HGST and memblaze devices. Is there any plan to add this to SPDK?