[PATCH 1/2] scsi: lpfc: avoid an unused function warning

[PATCH 1/2] scsi: lpfc: avoid an unused function warning

[Arnd Bergmann]

The only reference to lpfc_nvmet_replenish_context() is inside of
an #ifdef, leading to a harmless warning when CONFIG_NVME_TARGET_FC
is disabled:

drivers/scsi/lpfc/lpfc_nvmet.c:1457:1: error: 'lpfc_nvmet_replenish_context' defined but not used [-Werror=unused-function]

This replaces the preprocessor conditional with a C condition,
so the compiler can see that the function is intentionally unused.

Fixes: 9a38e4f1c82f ("scsi: lpfc: Fix MRQ > 1 context list handling")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/scsi/lpfc/lpfc_nvmet.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_nvmet.c b/drivers/scsi/lpfc/lpfc_nvmet.c
index 48a1c0c27a3f..0b7c1a49e203 100644
--- a/drivers/scsi/lpfc/lpfc_nvmet.c
+++ b/drivers/scsi/lpfc/lpfc_nvmet.c
@@ -1527,7 +1527,6 @@ lpfc_nvmet_unsol_fcp_buffer(struct lpfc_hba *phba,
 			    struct rqb_dmabuf *nvmebuf,
 			    uint64_t isr_timestamp)
 {
-#if (IS_ENABLED(CONFIG_NVME_TARGET_FC))
 	struct lpfc_nvmet_rcv_ctx *ctxp;
 	struct lpfc_nvmet_tgtport *tgtp;
 	struct fc_frame_header *fc_hdr;
@@ -1541,6 +1540,9 @@ lpfc_nvmet_unsol_fcp_buffer(struct lpfc_hba *phba,
 	uint32_t id;
 #endif
 
+	if (!IS_ENABLED(CONFIG_NVME_TARGET_FC))
+		return;
+
 	ctx_buf = NULL;
 	if (!nvmebuf || !phba->targetport) {
 		lpfc_printf_log(phba, KERN_ERR, LOG_NVME_IOERR,
@@ -1695,7 +1697,6 @@ lpfc_nvmet_unsol_fcp_buffer(struct lpfc_hba *phba,
 
 	if (nvmebuf)
 		lpfc_rq_buf_free(phba, &nvmebuf->hbuf); /* repost */
-#endif
 }
 
 /**
-- 
2.9.0

[PATCH v3 2/2] scsi: lpfc: avoid false-positive gcc-8 warning

[Arnd Bergmann]

This is an interesting regression with gcc-8, showing a harmless
warning for correct code:

In file included from include/linux/kernel.h:13:0,
                 ...
                 from drivers/scsi/lpfc/lpfc_debugfs.c:23:
include/linux/printk.h:301:2: error: 'eq' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
  ^~~~~~
In file included from drivers/scsi/lpfc/lpfc_debugfs.c:58:0:
drivers/scsi/lpfc/lpfc_debugfs.h:451:31: note: 'eq' was declared here

I managed to reduce the warning into a small test case for
gcc-8 that I reported in the gcc bugzilla[1].

As a workaround, this changes the logic to move the two assignments
of 'eq' out of the conditions and instead make the index conditional.
This works for all configurations I tried and avoids adding a bogus
initialization.

Acked-by: James Smart <james.smart@broadcom.com>
Link: [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81958
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/scsi/lpfc/lpfc_debugfs.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_debugfs.h b/drivers/scsi/lpfc/lpfc_debugfs.h
index 7b7d314af0e0..c4edd87bfc65 100644
--- a/drivers/scsi/lpfc/lpfc_debugfs.h
+++ b/drivers/scsi/lpfc/lpfc_debugfs.h
@@ -478,16 +478,16 @@ lpfc_debug_dump_cq(struct lpfc_hba *phba, int qtype, int wqidx)
 		return;
 
 	for (eqidx = 0; eqidx < phba->io_channel_irqs; eqidx++) {
-		eq = phba->sli4_hba.hba_eq[eqidx];
-		if (cq->assoc_qid == eq->queue_id)
+		if (cq->assoc_qid == phba->sli4_hba.hba_eq[eqidx]->queue_id)
 			break;
 	}
 	if (eqidx == phba->io_channel_irqs) {
 		pr_err("Couldn't find EQ for CQ. Using EQ[0]\n");
 		eqidx = 0;
-		eq = phba->sli4_hba.hba_eq[0];
 	}
 
+	eq = phba->sli4_hba.hba_eq[eqidx];
+
 	if (qtype == DUMP_FCP || qtype == DUMP_NVME)
 		pr_err("%s CQ: WQ[Idx:%d|Qid%d]->CQ[Idx%d|Qid%d]"
 			"->EQ[Idx:%d|Qid:%d]:\n",
-- 
2.9.0

Re: [PATCH v3 2/2] scsi: lpfc: avoid false-positive gcc-8 warning

[Martin K. Petersen]

Arnd,

> This is an interesting regression with gcc-8, showing a harmless
> warning for correct code:

Applied to 4.14/scsi-queue. Thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH 1/2] scsi: lpfc: avoid an unused function warning

[Martin K. Petersen]

Arnd,

> The only reference to lpfc_nvmet_replenish_context() is inside of an
> #ifdef, leading to a harmless warning when CONFIG_NVME_TARGET_FC is
> disabled:

Applied to 4.14/scsi-queue. Thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering