From: James Smart Date: Fri, 28 Aug 2020 17:53:30 +0000 (-0700) Subject: scsi: lpfc: Fix FLOGI/PLOGI receive race condition in pt2pt discovery X-Git-Tag: v5.15~2812^2~13 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7b08e89f98cee9907895fabb64cf437bc505ce9a;p=platform%2Fkernel%2Flinux-starfive.git scsi: lpfc: Fix FLOGI/PLOGI receive race condition in pt2pt discovery The driver is unable to successfully login with remote device. During pt2pt login, the driver completes its FLOGI request with the remote device having WWN precedence. The remote device issues its own (delayed) FLOGI after accepting the driver's and, upon transmitting the FLOGI, immediately recognizes it has already processed the driver's FLOGI thus it transitions to sending a PLOGI before waiting for an ACC to its FLOGI. In the driver, the FLOGI is received and an ACC sent, followed by the PLOGI being received and an ACC sent. The issue is that the PLOGI reception occurs before the response from the adapter from the FLOGI ACC is received. Processing of the PLOGI sets state flags to perform the REG_RPI mailbox command and proceed with the rest of discovery on the port. The same completion routine used by both FLOGI and PLOGI is generic in nature. One of the things it does is clear flags, and those flags happen to drive the rest of discovery. So what happened was the PLOGI processing set the flags, the FLOGI ACC completion cleared them, thus when the PLOGI ACC completes it doesn't see the flags and stops. Fix by modifying the generic completion routine to not clear the rest of discovery flag (NLP_ACC_REGLOGIN) unless the completion is also associated with performing a mailbox command as part of its handling. For things such as FLOGI ACC, there isn't a subsequent action to perform with the adapter, thus there is no mailbox cmd ptr. PLOGI ACC though will perform REG_RPI upon completion, thus there is a mailbox cmd ptr. Link: https://lore.kernel.org/r/20200828175332.130300-3-james.smart@broadcom.com Co-developed-by: Dick Kennedy Signed-off-by: Dick Kennedy Signed-off-by: James Smart Signed-off-by: Martin K. Petersen --- diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c index 48dc63f..abc6200 100644 --- a/drivers/scsi/lpfc/lpfc_els.c +++ b/drivers/scsi/lpfc/lpfc_els.c @@ -4656,7 +4656,9 @@ lpfc_cmpl_els_rsp(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb, out: if (ndlp && NLP_CHK_NODE_ACT(ndlp) && shost) { spin_lock_irq(shost->host_lock); - ndlp->nlp_flag &= ~(NLP_ACC_REGLOGIN | NLP_RM_DFLT_RPI); + if (mbox) + ndlp->nlp_flag &= ~NLP_ACC_REGLOGIN; + ndlp->nlp_flag &= ~NLP_RM_DFLT_RPI; spin_unlock_irq(shost->host_lock); /* If the node is not being used by another discovery thread,