[PATCH v2 1/5] scsi: elx: efct: check the HW state before allocating an HIO

[Ali Ahmet Memis]

efct_els_hw_srrs_send() takes an HIO from the pool and only then looks at
hw->state, returning without giving it back when the HW is not active:

	hio = efct_hw_io_alloc(hw);
	if (!hio) {
		pr_err("HIO alloc failed\n");
		return -EIO;
	}

	if (hw->state != EFCT_HW_STATE_ACTIVE) {
		efc_log_debug(hw->os,
			      "cannot send SRRS, HW state=%d\n", hw->state);
		return -EIO;
	}

_efct_hw_io_alloc() moves the entry from hw->io_free to hw->io_inuse and
initialises its reference, and the only thing that puts it back is the
completion of a submitted WQE. Nothing is submitted here, so the entry
stays on hw->io_inuse for the lifetime of the adapter. The memory is
reclaimed in efct_hw_teardown(), which frees hw->io[] as a whole, but the
pool loses one usable entry for every ELS or CT send that takes this
path. Once it is empty efct_hw_io_alloc() starts failing and no further
ELS or CT traffic can be sent.

Check the state first, the way efct_hw_bls_send() already does.

Fixes: dd53d333aadb ("scsi: elx: efct: Hardware I/O submission routines")
Signed-off-by: Ali Ahmet Memis <ali@xxxxxxxxxxxxxx>
---
 drivers/scsi/elx/efct/efct_hw.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/elx/efct/efct_hw.c b/drivers/scsi/elx/efct/efct_hw.c
index b79c6a7ea791..15c37ff1d52e 100644
--- a/drivers/scsi/elx/efct/efct_hw.c
+++ b/drivers/scsi/elx/efct/efct_hw.c
@@ -2706,18 +2706,18 @@ efct_els_hw_srrs_send(struct efc *efc, struct efc_disc_io *io)
 	u32 sge0_flags;
 	u32 sge1_flags;
 
-	hio = efct_hw_io_alloc(hw);
-	if (!hio) {
-		pr_err("HIO alloc failed\n");
-		return -EIO;
-	}
-
 	if (hw->state != EFCT_HW_STATE_ACTIVE) {
 		efc_log_debug(hw->os,
 			      "cannot send SRRS, HW state=%d\n", hw->state);
 		return -EIO;
 	}
 
+	hio = efct_hw_io_alloc(hw);
+	if (!hio) {
+		pr_err("HIO alloc failed\n");
+		return -EIO;
+	}
+
 	hio->done = efct_els_ssrs_send_cb;
 	hio->arg  = io;
 
-- 
2.55.0