bnxt_en: Do not process completion entries after fatal condition detected.

Once the firmware fatal condition is detected, we should cease
comminication with the firmware and hardware quickly even if there
are many completion entries in the completion rings.  This will
speed up the recovery process and prevent further I/Os that may
cause further exceptions.

Do not proceed in the NAPI poll function if fatal condition is
detected.  Call napi_complete() and return without arming interrupts.
Cleanup of all rings and reset are imminent.
Reviewed-by: NPavan Chebbi <pavan.chebbi@broadcom.com>
Reviewed-by: NVasundhara Volam <vasundhara-v.volam@broadcom.com>
Reviewed-by: NEdwin Peer <edwin.peer@broadcom.com>
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -2405,6 +2405,10 @@ static int bnxt_poll(struct napi_struct *napi, int budget)
 	struct bnxt_cp_ring_info *cpr = &bnapi->cp_ring;
 	int work_done = 0;
 
+	if (unlikely(test_bit(BNXT_STATE_FW_FATAL_COND, &bp->state))) {
+		napi_complete(napi);
+		return 0;
+	}
 	while (1) {
 		work_done += bnxt_poll_work(bp, cpr, budget - work_done);
 
@@ -2479,6 +2483,10 @@ static int bnxt_poll_p5(struct napi_struct *napi, int budget)
 	int work_done = 0;
 	u32 cons;
 
+	if (unlikely(test_bit(BNXT_STATE_FW_FATAL_COND, &bp->state))) {
+		napi_complete(napi);
+		return 0;
+	}
 	if (cpr->has_more_work) {
 		cpr->has_more_work = 0;
 		work_done = __bnxt_poll_cqs(bp, bnapi, budget);