net/bnxt: prevent device access in error state

[ upstream commit c967098 ]

Driver should prevent any DMA with the device when it
detects an error. When firmware is in fatal state,
stop tx/rx by assigning them to dummy functions.

Fixes: be14720 ("net/bnxt: support FW reset")
Fixes: 9d0cbae ("net/bnxt: support periodic FW health monitoring")

Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>

drivers/net/bnxt/bnxt_ethdev.c

@@ -4254,6 +4254,8 @@ static void bnxt_check_fw_health(void *arg)
 	bp->flags |= BNXT_FLAG_FATAL_ERROR;
 	bp->flags |= BNXT_FLAG_FW_RESET;
 
+	bnxt_stop_rxtx(bp);
+
 	PMD_DRV_LOG(ERR, "Detected FW dead condition\n");
 
 	if (bnxt_is_master_func(bp))