i40e: use minimal admin queue for kdump

The minimum size of admin send/receive queue is 1 and 2 respectively.
The admin send queue can't be set to 1 because in that case, the
firmware would fail to init.
Signed-off-by: Coiby Xu <coxu@redhat.com>
Tested-by: Dave Switzer <david.switzer@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/i40e/i40e.h

@@ -66,6 +66,8 @@
 #define I40E_FDIR_RING_COUNT		32
 #define I40E_MAX_AQ_BUF_SIZE		4096
 #define I40E_AQ_LEN			256
+#define I40E_MIN_ARQ_LEN		1
+#define I40E_MIN_ASQ_LEN		2
 #define I40E_AQ_WORK_LIMIT		66 /* max number of VFs + a little */
 #define I40E_MAX_USER_PRIORITY		8
 #define I40E_DEFAULT_TRAFFIC_CLASS	BIT(0)

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -15348,8 +15348,13 @@ static int i40e_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	i40e_check_recovery_mode(pf);
 
+	if (is_kdump_kernel()) {
+		hw->aq.num_arq_entries = I40E_MIN_ARQ_LEN;
+		hw->aq.num_asq_entries = I40E_MIN_ASQ_LEN;
+	} else {
 		hw->aq.num_arq_entries = I40E_AQ_LEN;
 		hw->aq.num_asq_entries = I40E_AQ_LEN;
+	}
 	hw->aq.arq_buf_size = I40E_MAX_AQ_BUF_SIZE;
 	hw->aq.asq_buf_size = I40E_MAX_AQ_BUF_SIZE;
 	pf->adminq_work_limit = I40E_AQ_WORK_LIMIT;