[PATCH net v2] bnxt_en: Gate TPH enablement behind BNXT_SUPPORTS_QUEUE_API check

In bnxt_request_irq(), pcie_enable_tph() is called unconditionally to
enable PCIe TPH when setting up interrupts.

If the NIC hardware or firmware capabilities do not support queue ops,
attempting to enable TPH during bnxt_request_irq() is unnecessary.

As a result a flood of "RX queue restart failed: err=-95"  messages is
seen upon boot.

Older NICs (pre-Thor / BCM57414) do not support TPH or queue management.
TPH requires queue management to restart the queue.  NICs that support
queue management (with updated FW) all support TPH.

Gate the call to pcie_enable_tph() and setting of bp->tph_mode
behind BNXT_SUPPORTS_QUEUE_API(bp) to ensure TPH is only initialized
on devices capable of supporting queue ops. This prevents a guaranteed
-EOPNOTSUPP error from occurring due to NULL operations.

Fixes: 1410c7416dc3 ("eth: bnxt: always set the queue mgmt ops")
Suggested-by: Michal Schmidt <[email protected]>
Signed-off-by: Thomas Walsh <[email protected]>
Reviewed-by: Michael Chan <[email protected]>
---
v2:
 - Updated commit message to include context on hardware support 
   and added Michael Chan's Reviewed-by tag.
 - Rebased onto net/main.

 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 9377bf675981..abe24d749cc2 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -11946,9 +11946,11 @@ static int bnxt_request_irq(struct bnxt *bp)
 #endif
 
 	/* Enable TPH support as part of IRQ request */
-	rc = pcie_enable_tph(bp->pdev, PCI_TPH_ST_IV_MODE);
-	if (!rc)
-		bp->tph_mode = PCI_TPH_ST_IV_MODE;
+	if (BNXT_SUPPORTS_QUEUE_API(bp)) {
+		rc = pcie_enable_tph(bp->pdev, PCI_TPH_ST_IV_MODE);
+		if (!rc)
+			bp->tph_mode = PCI_TPH_ST_IV_MODE;
+	}
 
 	for (i = 0, j = 0; i < bp->cp_nr_rings; i++) {
 		struct cpumask *cpu_mask = bp->ring_cpu_mask[i];
-- 
2.55.0