scsi: lpfc: Defer issuing new PLOGI if received RSCN before completing REG_LOGIN

scsi: lpfc: Defer issuing new PLOGI if received RSCN before completing REG_LOGIN

When mapped to a target with multiple virtual ports, a link bounce
sometimes results in unsuccessful rediscovery of all of the target's
virtual ports.  This is because a succession of repeat RSCNs for the
virtual target ports leaves ndlps in the REG_LOGIN state with the
NLP_REG_LOGIN_SEND flag set.  With NLP_REG_LOGIN_SEND set, during the next
PLOGI, the driver will UNREG_RPI.  When UNREG_RPI is processed, the driver
can be in the middle of PRLI_ISSUE or MAPPED state resulting in an illegal
state transition by the discovery engine and stalling.

Fix by calling the discovery state machine with DEVICE_RECOVERY event
during RSCN processing.  This will set the NLP_IGNR_REG_CMPL bit and
prevent the old REG_LOGIN state from advancing.  Then for the new PLOGI
issue, add the check for the NLP_IGNR_REG_CMPL bit to delay issuing the new
PLOGI until the queued REG_LOGIN and UNREG_LOGIN have been processed.

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20230301231626.9621-6-justintee8345@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>